In order to reduce the workload of data reporting for drilling site operators and standardize the data reporting process, a drilling data push platform based on CNPC Instant Messenger has been designed and developed. By analyzing the current business status and demands, it clearly takes CNPC Instant Messenger as the push channel, and determines the push content and push strategy. The drilling data push platform software is developed based on .NET framework and applied to production data push. The practice has shown that using CNPC Instant Messenger for data push has the characteristics of high automation and safer data compared to manual data reporting, which helps to improve the work efficiency of data reporting and the level of enterprise informatization management.

After 30 years of exploration and development, domestic coalbed methane is mainly concentrated in coal seams within 1200 meters. However, with the gradual depletion of shallow coalbed methane resources, the utilization of deep coalbed gas resources has become a trend. In view of the fact that mud logging belongs to a new field in the evaluation of deep coal and rock gas, many new drills for deep coal and rock gas have been tackled in the past two years around mud logging parameter optimization and "dessert" evaluation. The mud logging technology series suitable for unconventional reservoir of coal measures is selected with the combination of previous service results in the domestic shallow coal measures gas market, and the reservoir situation is revealed from 4 aspects: lithology, brittleness, hydrocarbon source rock characteristics and gas-bearing properties. Finally, the mud logging classification and evaluation method of deep coal and rock gas is formed. This method has been successfully applied to the evaluation and fracturing layer selection scheme design of 15 deep coal-rock gas wells in Changqing, which shows the technical advantages of multi-information comprehensive evaluation of mud logging technology and meets the development needs of unconventional reservoir exploration of deep coal rock gas.

In the previous application of thermal evaporation hydrocarbon gas chromatography analysis technology, the reservoir characteristics were mainly determined based on the peak type, carbon number range, main peak carbon and other parameters of normal paraffin hydrocarbons, while the carbon number distribution characteristics of associated unidentifiable alkanes such as isoalkane were rarely researched. For example, for the oil and gas layers in Dongying depression, it is found through experimental observation that the values of the unidentifiable alkanes have a certain correlation with the water content of the oil and gas layers. Therefore, the correlation between unidentifiable alkanes and water content in oil and gas layers is researched. First, the unidentifiable alkanes generated in thermal evaporation hydrocarbon gas chromatography analysis are partitioned and named, and the peak area is read. Then the individual partition peak area is superimposed to calculate the total peak area of unidentifiable alkanes. Finally, two parameters, the ratio of the total peak area of unidentifiable alkanes to the quantitative total peak area of thermal evaporation hydrocarbon and the ratio of the total peak area of unidentifiable alkanes to the total peak area of normal paraffin hydrocarbons, are used to assist in the comprehensive interpretation and evaluation of reservoir oil, gas, and water layers. Field application shows that this method can effectively improve the interpretation accuracy.

The reef limestone reservoir in LF X-1 oilfield is a structural edge water reservoir as a whole, with strong reservoir heterogeneity, great changes in oil abundance and oil properties, complex pore water types, and low permeability reservoirs containing capillary water, which is difficult to identify by conventional well logging. However, geochemical logging is very sensitive to the reservoir oil saturation,oil properties and water-bearing response characteristics, so it has obvious technical advantages for evaluating reservoirs with low resistivity and low gas logging shows in this oilfield. The geochemical logging responses of reservoirs with different pore water types have both commonness and individuality. The commonness refers to the decrease of oil abundance after the reservoir contains water, which is manifested as the decrease of total hydrocarbon content and total hydrocarbon area of the chromatogram, and the deterioration of oil properties become poor, which are manifested as the decrease of oil yield index. Individuality means that the low permeability reservoirs contain capillary water, characterized by an increase in Pr/Ph. Conventional reservoir contains free water, which is manifested as a significant increase in Pr/nC₁₇ and Ph/nC₁₈. Good results have been obtained in water bearing identification of reef limestone reservoirs of 6 development wells in LF X-1 oilfield by using geochemical bright spots and other geochemical logging characteristic parameters, and the coincidence rate of reservoir interpretation is over 90%. The application results show that geochemical logging plays an important role in reservoir evaluation,water bearing identification and geosteering while drilling.

In order to make NMR logging technology play a more important role in oil-gas field exploration and development, the applicability of the cuttings NMR logging was discussed by taking the tight sandstones of Sichuan Basin as the object of study. The NMR porosity and permeability of rock cuttings with the same interval and different particle diameters were analyzed. The mathematical models of cuttings NMR porosity and core lab determining porosity, cuttings NMR permeability and core lab determining permeability were established. The study shows that for the same plunger core sample, the correlation coefficients （r values） of NMR porosity and core lab determining porosity, NMR permeability and core lab determining permeability are 0.99 and 0.86, respectively. For rock cuttings with the same interval and different particle diameters, NMR porosities and core lab determining porosities, NMR permeabilities and core lab determining permeabilities are compared. As the particle diameters of rock cuttings decrease, the correlation coefficients （r values） decrease and the correlations become worse. For the particle diameters of rock cuttings are not less than 3 mm, the correlation coefficients （r values） between NMR porosities and core lab determining porosities are not less than 0.90, the correlation coefficient （r values ） between NMR permeabilities and core lab determining permeabilities are not less than 0.73. The results show that the particle diameters of PDC bit cuttings in mud logging site can also meet the application of NMR logging technology.

The change of drilling fluid volume parameter is a direct indication of the increase or decrease of drilling fluid found in time, and is also a key parameter for judging and preventing overflow and circulation loss. As the drilling fluid is stirred by the agitator, the liquid level fluctuates violently, which causes certain errors in the monitoring of drilling fluid volume parameter by the comprehensive mud logging unit, and affects the abnormal judgment of drilling fluid parameters such as overflow and circulation loss, which is also a difficult point in the mud logging operation. Therefore, a drilling fluid tank liquid level anti-fluctuation device has been developed, which is composed of hollow anti-fluctuation pipe,installation of collar clamp, sensor mounting bracket and other components, which can greatly reduce the influence of drilling fluid agitator. By installing two sensors of the same model at the same window on site for monitoring and comparison, it is found that the anti-fluctuation device for the drilling fluid tank liquid level effectively reduces the interference of liquid level fluctuations, improves the accuracy of monitoring key well control parameters such as overflow and circulation loss, provides a scientific basis for real-time decision-making in drilling engineering, and plays an important role in ensuring well control safety.

In recent years, NMR logging has achieved remarkable application effect, which can realize rapid analysis of field rock physical properties, evaluation of pore structure, quantitative analysis of important parameters such as hydrocarbon saturation, movable fluid saturation, and irreducible fluid saturation. However, in terms of fluid property identification, due to the influence of T₂ cutoff value, there are slight errors in the calculation of important parameters such as movable fluid saturation, irreducible fluid saturation, and pore size distribution, which restrict the further development of NMR logging technology. The NMR spectra are processed by introducing the segmentation technique of NMR spectra (segmented according to transverse relaxation time), the reconstructed signal is obtained and calculated again, and the oil saturation and porosity in the 1-10 ms segment are optimized to establish a two-dimensional interpretation chart. The application of later data has achieved good results, with the interpretation coincidence rate from 75.6% to 81.6%, improving the accuracy of NMR logging interpretation and evaluation, which can meet the needs of rapid identification of fluid properties in the field.

In southern Sichuan region of the Sichuan Basin, the geologic structure is complex and the formation deformation strength is different, so it is difficult to model the fine 3D seismic velocity. In the past, seismic velocity modeling focused more on the iterative correction of the horizontal section of the deep target bed, but the complex working conditions （gas invasion, overflow, leakage, casting, etc.） frequently occurred in the shallow non-target bed of the cluster platform well, which seriously affected the drilling time and construction safety, it is urgent to establish a fine seismic velocity model that takes into account both deep and shallow layers for time-depth conversion. Based on 3D time domain seismic data, the initial seismic velocity model is established by precise artificial synthetic seismogram calibration, combining horizon data and well data, and then the virtual control well is set up by referring to the actual drilling data of adjacent wells. The initial seismic velocity model is optimized by combining the minimum curvature interpolation with inverse distance weighted interpolation, which can quickly realize the simultaneous iterative correction in deep and shallow layers. Finally, a fine 3D seismic velocity model conforming to the tectonic sedimentary characteristics is obtained. Using the corrected 3D seismic velocity model, the time-depth conversion data can provide timely and accurate risk warning and geosteering suggestions for the whole strata in drilling engineering. This technology has remarkable effect in on-site geosteering while drilling in the southern Sichuan region and can be widely applied.

In oil-gas exploration and development, the space for innovation in exploration and development technology relying on existing models is becoming increasingly limited, the existing information and digitization achievements are no longer able to support the new demand for increasing oil-gas reserves and production, reducing costs and increasing efficiency. Years of exploratory practice in the domestic oil and gas exploration field has shown that implementing geology-engineering integration is the only way to reverse the trend of declining oil-gas reserves and achieve high-quality exploration and development. To this end, a set of application scheme integrated engineering implementation and geological research is proposed. On the basis of integrating existing oil-gas exploration and development information system resources and application modules, and solving various technical defects and application problems in the existing system, a multi-professional integrated collaborative decision-making platform of geology and engineering with big data and core business system integration of oil-gas exploration and development is constructed. The platform adopts a standardized four-layer structure model, including data acquisition layer, network support layer, data storage layer and data application layer. It is composed of 7 core modules, such as mud logging data acquisition, processing and interpretation, and mud logging geological big data application. It can provide integrated service support for digitization innovation of oil-gas exploration and development, covering mud logging data acquisition, interpretation and evaluation, drilling engineering construction, geological synthesis study and other businesses. The construction and application of this platform have achieved good economic and social benefits, becoming an important driving force for expanding business, improving quality and efficiency, and continuously promoting the comprehensive transformation of various majors in oil-gas exploration and development from digitization to intellectualization.

To solve the influence of wellbore pressure fluctuation on the detection results of total hydrocarbon data of gas logging, a gas logging simulation experiment apparatus was designed under the condition of simulating wellbore pressure fluctuation. Simulation experiments were conducted on relevant influencing factors, and calibration standards for total hydrocarbon detection values were established based on experimental data. The experimental results show that the total hydrocarbon detection values decrease with the increase of drilling fluid densities, and first increase and then decrease with the viscosities of drilling fluid. The detection value reaches the maximum when the viscosity of drilling fluid is 60 s.The total hydrocarbon correction models have been applied to the reevaluation of 25 old wells and 8 newly drilled wells in Wen′an slope, and the interpretation coincidence rate is 84.6%, an increase of 5%, which effectively solve the problem that the total hydrocarbon detection values of gas logging are influenced by drilling fluid properties under the condition of wellbore pressure fluctuation.

With the development of unconventional reservoirs in recent years, the complexities of oil and gas exploration have risen significantly, and subsurface fluid relations have become more and more complex. The demand for rapid and accurate evaluation of formation fluids, discovery of thin, fracture-type, and weakly show of oil and gas layers, and provision of decision-making basis for exploration and development has become more urgent. Aiming at the difficulties of identifying thin interlayers in complex reservoirs and recognizing the nature of unconventional oil and gas fluids, we have carried out research on infrared spectrum logging featured technology based on the spectroscopic principle of gas molecular. This technology has an analysis period of ≤8 s, and is not easy to leak oil and gas layers under rapid drilling conditions. In particular, it has more technical advantages in fluid evaluation of oil, gas and water layers while drilling, identification of fractured/thin hydrocarbon reservoirs, fine classfication of reservoirs and boundary determination. Based on the infrared spectrum gas logging technology, the reservoir energy level spectrogram evaluation model and the evaluation standard of reservoir fluid properties are established. The practical application of this method in the well site has achieved good results and effectively solved the problem of reservoir fluid identification and evaluation under rapid drilling conditions.

Gas logging technology is currently one of the important methods for quickly and accurately judging hydrocarbon reservoirs in drilling sites. However, gas logging data is affected by many factors, resulting in a decrease in the accuracy of gas logging data. At present, there have been many studies on the influence factors of gas logging data, but few studies on the influence of flow pattern changes in gas-liquid two-phase flow in the wellbores on gas logging data. Therefore, a gas logging experimental apparatus using spiral pipe instead of straight pipe is specially designed, and the feasibility of this experimental apparatus is verified. Then, based on Fluent software, a spiral pipe numerical model with the same parameters as the gas logging experimental apparatus is established. And based on this model, the generation conditions of various flow patterns (bubbly flow, slug flow, piston flow, annular flow, and mist flow) in gas logging experiment are provided. Finally, based on the experimental apparatus of gas logging and the generation conditions of each flow pattern, the experiment is carried out for the influence of flow pattern changes in gas-liquid two-phase flow on gas logging. The results are obtained in three aspects. First, the total hydrocarbon detection values increase with the flow patterns (bubble flow → slug flow → piston flow → annular flow → mist flow), and there are still significant differences in the total hydrocarbon detection value changes caused by different flow pattern transitions. Second, the total hydrocarbon detection values under different flow patterns decrease with the increase of drilling fluid density, and the degree of influence of drilling fluid density on gas logging data decreases with the changes of flow patterns. Third, the total hydrocarbon detection values under different flow patterns all increase first and then decrease with the increase of drilling fluid viscosity, and the sensitivity of the influence of drilling fluid viscosity on gas logging data decreases with the changes of flow patterns. By studying the flow pattern influence of two-phase flow on gas logging data, the correction accuracy of gas logging data is further improved.

In order to ensure the drilling safety in the coastal area of Dagang Oilfield sag, and improve the drilling efficiency to the maximum extent, this article starts with the complex drilling situation in the coastal area, analyzes the main geological factors and reasons that cause drilling risks in this area. Meanwhile, corresponding solutions are proposed. The research shows that： （1）The Neogene Guantao Formation in the research area has shallow buried depth, loose rock structure and unconformities developed at the bottom.The Paleogene Shahejie Formation has deep burial, high original formation pressure and high gas-oil ratio, which lead to high drilling risks in this area.（2）The complex situation of drilling underground can be mainly divided into two categories. One is leakage type, mainly well leakage. The other is overflow type, including gas invasion, overflow, and well kick. （3）The geological risks of complex well conditions in the research area are mainly the weakly consolidated gravel at the bottom of the Guantao Formation and the unconformity surface at the bottom of the Guantao Formation. The geological risk of overflow type complex well conditions mainly lies in the abnormal high pressure and abundant gas volume of the Shahejie Formation. （4）The measures to deal with the geological risks of complex well conditions caused by leakage mainly lie in investigating the spatial distribution of sand and gravel at the bottom of the Guantao Formation. The measures to deal with the geological risks of overflow type complex well conditions mainly lie in timely pressure measurement,and adjust the drilling fluid density in real time in the process of drilling. The research results of this article can provide reference for drilling work in coastal areas and areas with similar geological conditions.

Geochemical logging is often affected by engineering, geological conditions, and human factors, resulting in hydrocarbon losses of rock samples from the bottom of the well to the surface. It fails to reflect the real oil and gas content information of underground reservoirs well, and a reasonable and accurate method is needed to restore hydrocarbon losses. In view of the relationship between cuttings values（independent variables） and wall core values （dependent variables） at different horizons in different areas of the Bohai Sea, based on least square method, gradient descent method and its derivative algorithm, the paper fits the data of sidewall coring in the study area using two methods： multiple linear regression and non-linear regression. The model of multiple linear regression can be fitted by regression using normal equation, ridge regression, LASSO （Least Absolute Shrinkage and Selection Operator） and elastic net. The non-linear regression model can use the gradient descent method and the piecewise function fitting method. The analysis and comparison of different regression analysis methods show that ridge regression has good results in calculating the hydrocarbon losses of linear relationship, with the determination coefficient r² exceeding 0.7. Piecewise function fitting based on ridge regression and nonlinear regression model y=x/（b+kx） are suitable for non-linear hydrocarbon loss restoration. Compared with the traditional method of hydrocarbon loss restoration, using the quantitative method to restore hydrocarbons in the study area is more scientific and comprehensive, and has a broad prospect of application.

Compared to the exposed buried hills in Bozhong sag, the covered buried hills are buried deeper with an average well depth of over 4 200 m. The lithology of the overlying strata is more complex, and the difference in drillability of the strata at the interface is smaller. It is difficult to select geological circulation points for the buried hill interface determination, and the operating efficiency is low. By conducting statistical analysis on the situations of the buried hill interface determination and the changes in drilling parameters at the covered buried hill interface in the drilled wells of Bozhong sag in recent years, an innovative error probability model of buried hill interface prediction in Bozhong sag was proposed. By screening out the sensitive parameters of buried hill interface determination, calculating the change rate and weight coefficients of the parameters, a comprehensive evaluation index for the buried hill interface determination was formed, and a geological circulation index model for Bozhong sag was established. The application effect of the method is good in the operation of the covered buried hill wells in Bozhong sag. The operating efficiency has been significantly improved.

With the continuous expansion of production scale in petrochemical enterprises, the types of chemicals involved are also increasing. However, due to the special characteristics and usage of chemicals, there are some risks and hidden dangers in the management and use of chemicals. At present, mud logging companies still adopt the method of traditional manual paper standing book for chemicals management, which has problems such as low management efficiency, poor chemicals traceability ability, and inadequate use and monitoring. Based on WeChat mini programs, a set of chemicals management system is developed. The system architecture, functional modules, and technical implementation are introduced from two aspects： software design and implementation. Application testing is conducted on the mud logging site. The system achieves the precise management of the whole process life cycle of chemicals through the mobile terminal, improving the management efficiency and quality of chemicals.

In the process of lithology identification, element logging interpretation is relatively simple and less accurate, especially in geosteering.A set of element logging horizontal well geosteering method is established by using chemometrics method, and the difference characteristics of different lithology of target layer, upper surrounding rock layer and lower surrounding rock layer of horizontal well are analyzed by computer and mathematical methods. Starting from the complex element measurement data, the principal component analysis and included angle cosine similarity analysis are used to analyze and form a visual two-dimensional drawing board. The trajectory adjustment scheme is given to guide the bit to drill horizontally in the target layer. This method has been applied in many key horizontal wells in Ordos Basin, and good application results have been obtained, which improves the reservoir drilling rate of horizontal wells and provides useful information for the overall study of horizontal wells.

The polycyclic superimposed basins in China are characterized by multiple phases of hydrocarbon generation, multiple phases of hydrocarbon charge, multiple phases of hydrocarbon accumulation and alteration under the background of multi-stage tectonic movements, and it has always been a challenge to be solved for research on hydrocarbon accumulation in polycyclic superimposed basins to accurately determine the timings of hydrocarbon charge in different phases. The current research status and development trend of hydrocarbon accumulation geochronology are reviewed, and the main features and limitations of different hydrocarbon accumulation geochronological methods are systematically analyzed. It is believed that the study of hydrocarbon accumulation geochronology has experienced the development from the traditional hydrocarbon accumulation geochronology method in the early period to the isotope dating method in the present, which has realized an important transition from qualitative or semi-quantitative to quantitative study. Among them, the laser in-situ U-Pb dating of calcite can accurately determine the timings of different phases of hydrocarbon charge in polycyclic superimposed basins and pushes the study of hydrocarbon accumulation geochronology to a new milestone. It is proposed that the integrated use of multiple hydrocarbon accumulation geochronological methods to complement and corroborate each other to obtain comprehensive geochronological information, which will become an important trend in the development of modern hydrocarbon accumulation geochronology in polycyclic superimposed basins.

Carbon isotope logging can be used to study the composition and distribution of carbon isotopes in underground oil and gas, for determining oil and gas maturity and identifying sweet spots. Currently, isotope mass spectrometry and isotope spectroscopy are mainly used for off-line detection of manual injection samples. Due to their low efficiency and inability to ensure accuracy, they cannot meet the real time mud logging requirements, therefore a set of automatic sampling system has been developed to detect methane, ethane and propane carbon isotopes of formation gas in real time. The system can communicate with the comprehensive mud logging units, transmit the real time formation gas logging data readout to the carbon isotope analyser, perform matching dilution operations based on gas logging concentration, and cooperate with the chromatographic control and spectral detection units of the back-end carbon isotope analyser to complete fully automatic real time carbon isotope measurement. It improves the analysis speed and measurement accuracy of on-site carbon isotope logging, reduces the labor intensity of field personnel, and provides effective technical support for identification of SG&O and geofault.

The fluid types of hydrocarbon reservoirs in Pinghu slope belt of Xihu sag are complicated. According to the PVT phase behavior analysis results, the reservoir fluids are mainly condensate gas and volatile oil. There is no obvious difference in the response characteristics of mud logging and well logging data, which makes it difficult to quickly identify the fluid phases of hydrocarbon reservoirs while drilling at the well site. The fluid phases of hydrocarbon reservoirs are the key physical property parameters for productivity evaluation, reserve scale implementation and development plan formulation. The traditional fluid phase identification method is mainly obtained through downhole PVT sampling analysis, with high cost and operating risk. By investigating the previous research results, the PVT analysis data from 18 layers of 4 wells accumulated in Pinghu slope belt were combined with the algorithm. First, the Pearson product-moment correlation coefficient （PPMCC） was used to conduct linear correlation analysis on 9 forward parameters, and 5 highly correlated parameters were optimized as radar chart ray parameters. A radar chart for fluid phases of the Pinghu slope belt was established. Then, with the gas-oil ratio and density of the hydrocarbon reservoir fluid as the dependent variables, and the coverage area of the five forward parameters in the radar chart as the independent variables, the multiparameter gas-oil ratio and density prediction models are established by using multiple linear regression to clarify the quantitative relationship between the coverage area of the forward parameters in the radar chart and the gas-oil ratio and density of the hydrocarbon reservoirs. Based on PPMCC data analysis, C₂/C₃、（C₁+C₂）/（C₃+C₄+C₅）、C₂/（C₃+C₄）、C₁/C₃、（C₁+C₂+C₃）/（C₄+C₅）, a total of 5 parameters are optimized to form a radar chart. The multiparameter gas-oil ratio and density prediction models established from the geometric model have been verified and applied in 14 layers of 5 wells. The average prediction errors for gas-oil ratio and density are 11.55% and 4.71%, indicating that the established models can realize the rapid and accurate classification of hydrocarbon reservoir types,and the application effect is obvious.

The Qiongzhusi Formation in southwestern Sichuan is a new hot spot of deep marine shale gas in Sichuan Basin. In order to deepen the geological understanding and explore the mechanism of low organic carbon but high yield, this paper calculates the ratio of related elements by using geochemical method and based on logging, experimental analysis data, and conducts correlation analysis with TOC (Total Organic Carbon) to study the influencing factors and organic matter enrichment patterns of organic matter enrichment. The results show that the main influencing factors of organic matter enrichment are paleosedimentary environment, paleoproductivity, paleotergenous input, etc., and the enrichment of organic matter is positively correlated with phosphorus, zirconium and other elements. It is believed that the basic conditions for the accumulation of organic matter in this area are strong paleoproductivity and rapid sedimentation of terrigenous inputs, and an oxygen-poor reducing environment is formed under the condition of good overlying cover. Based on the logging elements, the machine learning algorithm is used to obtain the organic carbon content while drilling, and the difference in the distribution of organic matter in the trajectory direction of horizontal wells is explored, which provides more abundant materials for deepening the understanding of shale gas accumulation in this area.

The shallow fluvial facies oil fields in Bohai Sea are characterized by thin reservoirs and rapid sand body facies change. During the landing process of horizontal wells, there are great uncertainties in the structural depth of target layers and the plane distribution of sand bodies, at the same time, the landing of horizontal well is very difficult because of the limitation of conventional boundary detection tools and common prediction methods. In order to improve the landing success rate of thin-layer horizontal wells, the ultra-deep boundary detection geological guidance method is introduced, and the depth of target layer is predicted by the ability of long-distance detection of formation information during horizontal well landing, to achieve proactive orientation adjustment. The successful application of A well in Bohai K Oilfield 4-1 zones proves this method can accurately predict the target layer position in fluvial facies reservoir with complex geologic conditions and improve the landing success rate of horizontal well.

The sedimentary type of Ed₃ Formation in Bohai A Oilfield is braided river delta, well drilling shows that sandstone percent content is between 5%-65%, and in several areas, igneous rocks with thickness of 5.4-22.6 m are distributed as layers in the inner reservoir. Ed₃ Formation can be divided into four lithology-sedimentary facies belt which develop layered igneous rocks, underwater distributary channel, distal-bar sand and sheet sand. Accurate well-seismic calibrating shows that different stratigraphic lithologic structure can be distinguished by seismic amplitude attribute. In the paper, seismic forward models with complicated stratigraphic lithologic structure are designed, to establish mathematical relations of amplitude attribute and sandstone content, result shows that RMS amplitude is 1 160-4 808 and has a three-part relationship with sandstone content when stratigraphic is sand-shale interbedding. RMS amplitude is higher than 7 226 when stratigraphic is sand, shale and igneous rocks interbedding. Sandstone content is in reverse proportion to RMS amplitude. The sandstone content of Ed₃ Formation is described quantitatively in different zones with well drilling correction. The result is applied to fine geologic modelling. 20 development wells have been deployed, the average single well sandstone drilling rate is increased by 22.3% and recovery ratio is increased by 1.2% through model prediction.

Accurate identification of site lithology plays an important role in oil and gas exploration and development. As the difficulty of exploration increases, the difficulty of lithology identification on site also increases accordingly. An intelligent identification method of lithology based on data while drilling is proposed to solve the problem of on-site stratigraphic lithology identification while drilling. This method analyzes the formation elements and parameters while drilling, extracts the eigenvectors, establishes the multiple-feature collection library of different lithology, and realizes the lithology intelligent identification based on data while drilling by using the generalized regression neural network model of the Max-Min Ant System optimization algorithm.This method is applied to actual lithology identification while drilling, and the MMAS-GRNN model constructed from non-feature extraction data and feature extraction fusion data is compared.The experimental results show that the accuracy rate of stratigraphic lithology identification of MMAS-GRNN model based on multi-source information feature extraction fusion data reaches 90.71%, which is 4.76% higher than that of non-feature extraction data model, showing the superiority of multi-source data after feature extraction fusion in stratigraphic lithology identification effect.

The south bank of Tarim river is one of the main areas for exploration and development of the Tarim Oilfield to increase reserves and production, with deep and ultra-deep layers as the main exploration targets. However, due to the development of Permian igneous rocks, frequent incidents of lost circulation and stuck occur during the drilling process, which seriously restrict the drilling speed. To this end, in the drilling and completion stages, the complexity early warning of downhole accidents is carried out in advance through the geology-engineering integration technology, so as to reduce the complexity of engineering accidents in the drilling process. That is, before drilling, seismic, well logging and mud logging identification methods are used to summarize the distribution of igneous rocks and the combination of igneous rock facies, to predict the lithology of a single well, to establish a geological risk prediction template, to guide the selection of drill bits, and to formulate lost circulation prevention measures in advance. During drilling, the combination of mud logging technologies such as elements, whole rock, rock thin section identification, and scanning electron microscope is used to identify igneous rock lithology from the perspective of "chemical composition + microstructure", establish igneous rock identification criteria, carry out igneous rock lithology identification, and achieve accurate site layer determination, fracture identification, drillability evaluation, so as to conduct real-time risk early warning. Post drilling, the construction experience is summarized, and the penetration rate improvement template for safe drilling in Permian igneous rock sections is perfected, which provides guidance for subsequent drilling. The geology-engineering integration technology provides technical support of the geology for the optimization of drilling construction in igneous rock development area, effectively reduces the regional accident complexity rate, and improves time efficiency of drilling.

Making abnormal high pressure prediction while drilling in carbonate reservoirs is the key to reduce the probability of overflow and lost circulation risks. In view of the prediction problem of abnormal high pressure in Yijianfang Formation-Yingshan Formation carbonate reservoirs of Fuman area, Tarim Basin, the porosity and fracture number related to abnormal high pressure in fault-controlled fracture-cavity carbonate reservoirs are obtained through rock and mineral scanning logging technology, the fracture complexity index reflecting the complexities of fractures is introduced, and the porosity and fracture complexity index chart is established to identify and predict the abnormal high pressure in Yijianfang Formation-Yingshan Formation carbonate reservoirs of Fuman area, Tarim Basin. Taking well FD 1 in Fuman area of Tarim Basin as an example, the application of porosity and fracture complexity index chart can effectively characterize abnormal high pressure sections of carbonate reservoirs, providing a new method for the study and prediction of abnormal high pressure of carbonate reservoirs in this area, and also providing technical support for further exploration and development to take engineering measures in advance to reduce the probability of overflow and lost circulation risks.

By analyzing the gas logging, geological logging, gas content measurement, and isothermal adsorption test data of Zhangye 1 well constructed in the eastern part of Xuanhua, Hebei Province, the comprehensive gas-bearing properties of the coal bearing strata in the area is evaluated. Finally, it is confirmed that there are multiple layer, thin layers, and obvious vertical spatial stacking characteristics of dark shale, coal seams, and dense sandstone sedimentary strata in the Xiamaling Formation of the Qingbaikou System and Xiahuayuan Formation of Middle-lower Jurassic System in the area. Gas logging reveals 8 abnormal gas layers, all present in the Xiahuayuan Formation. Gas content data shows that the total gas content of the shale layer is between 1.10 m³/t-8.30 m³/t, with an average of 3.60 m³/t, and the total gas content of the coal seam was between 2.78-14.80 cm³/t, with an average of 7.17 cm³/t. Isothermal adsorption experiments shows that the Langmuir volume of the shale is between 3.33-6.49 cm³/g, with an average of 4.78 cm³/g, and the Langmuir volume of the coal seam is between 12.29-21.67 cm³/g, with an average of 17.75 cm³/g. The gas chemical composition is mainly methane. Through methane isotope analysis of coalbed methane, it is shown that the genesis of coalbed methane in this area is complex, including thermal, biogenic, and secondary thermal genesis. It shows that the area has good comprehensive gas-bearing properties in coal bearing strata.

Total hydrocarbon data is an important parameter in the interpretation and evaluation. Because the form evaluation of total hydrocarbon shape mainly depends on visual identification, and the subjective factors account for a large proportion, which cause certain limitations to its application effect. In order to realize the quantitative evaluation of the forms of total hydrocarbon peak shapes, the absolute area of total hydrocarbon peak shape is calculated by trapezoidal segmentation based on the basic principle of total hydrocarbon curve. Then the calculation method of total hydrocarbon peak shape relative area is proposed by the ratio of the absolute area and the rectangular area. The interpretation and evaluation charts are established based on absolute area and relative area of total hydrocarbon peak shapes, the maximum value of total hydrocarbons and the relative percentage content of methane, and the charts have a good effect on distinguishing fluid properties. The method has been applied and verified in Chaheji oilfield of Baxian sag, with a coincidence rate of 77.3%, which can meet the production demand and provide a new method for quantitative evaluation of the forms of total hydrocarbon peak shapes.

In oil and gas exploration, it is of great significance to identify the genetic type of natural gas while drilling, it can reflect important oil & gas geological information in real time. At present, there are few methods to identify the genetic types of natural gas while drilling. In view of the diversity of identification methods, Baiyun Sag is chosen as the study area, using FLAIR mud logging technology. The genetic types of natural gas identified by ethane carbon isotope and corresponding three FLAIR mud logging sensitive parameters C₇H₁₄, nC₇ and C₇H₈ are studied. The identification method of C₇ light hydrocarbon system triangular plot is used for reference to establish a new method for identifying natural gas genetic types in Baiyun Sag. The results show that FLAIR sensitive parameters closely related to the genetic type of natural gas are used, a new triangular plot identification method for C₇ light hydrocarbon system is set up, oil type gas and coal-related gas can be accurately identified, it obtains good application effects in identification while drilling, provides important data basis for the study on oil and gas reservoir forming characteristics and migration and accumulation distribution system, and is of popularization value.

Natural gamma energy spectrum logging technology plays an important role in lithology identification, stratigraphic division, reservoir identification and other aspects. However, operational differences among operators, drilling coring during the drilling process and insufficient cuttings caused by drilling complexities such as lost circulation can all lead to measurement data deviations. By conducting experiments on influence factors of natural gamma energy spectrum data, the influence degree of the sensing time, cuttings sample filling pattern, the coarse or fine of the cuttings grains,the dry or wet degree of the samples, and sample mass on measurement data were analyzed. It is considered that sample mass is the most important factor influencing natural gamma energy spectrum logging, and the total dose rate of its radiation has a linear relationship with cuttings mass. Based on the experimental conclusions, a set of standardized operations suitable for the field has been formed. When the sampling conditions are limited and the sample mass is insufficient, parameter correction can be performed using the linear relationship between the total dose rate of the radiation gamma and the sample mass.

With the continuous breakthroughs in shale oil and gas exploration and development, the "Well Factory" model came into being in order to meet the needs of the shale oil and gas drilling factory construction model and the integrated construction of drilling, well logging, mud logging, and directional well. However,in many aspects such as well site construction, rear management and data application, the profession of drilling, well logging, mud logging, and directional well operates independently and lacks coordination and management methods. Therefore, business operations are scattered, software is difficult to integrate, data is difficult to share, and there is a lack of a unified comprehensive application platform to meet the need of "Well Factory" model. With the help of the "Well Factory" model, a cross-professional, cross-regional, and cross-organizational integrated decision support platform has been built, which can realize the organic fusion of various professional technologies, real-time sharing, and collaborative linkage among multiple parties. The platform meets the needs of integrated geological engineering construction and has reference significance for the construction and development of intelligent oil and gas fields.

Due to the significant heterogeneity and intricate gas-water relation of the tight sandstone gas reservoirs in Sulige Gas Field, there is a limited distinction in fluid logging response characteristics. Consequently, this leads to a low coincidence rate in identifying the reservoir fluid properties for the conventional logging parameters cross-plot interpretation methods, making it challenge to effectively identify gas layers. A new gas-water identification method for tight sandstone reservoirs is established based on grey relational and principal component analysis methods. 112 gas test reservoirs from 30 wells in the southwestern part of Su 20 block are selected as analysis samples. First, the grey relational method is used to select 5 logging response parameters, which are the most sensitive to the change of reservoir fluid properties, namely interval transit time, compensated density, compensated neutron, porosity and the difference（A₁） in amplitude between internal transit time and compensated neutron curves. On this basis, principal component variables from Y₁ to Y₅ independent from each other are constructed based on the principal component analysis method, and principal components Y₁ and Y₂, with a cumulative variance contribution rate of 86.99%, are selected to synthesize the raw information reflecting the multidimensional logging variables. Finally, Fisher linear discriminant method is used to establish a gas-water quantitative interpretation model. The new method recognizes the reservoir fluid properties by integrating the information of multiple logging sensitive parameters, the overall interpretation compliance rate is 86.6%, and the gas layer interpretation compliance rate reaches 92.3%, which is an obvious improvement in the recognition efficiency compared with the conventional crossplot chart method. At the same time, the new method is effective in practical application on Member 8 of Shihezi Formation, which further indicates that the new method can provide effective technical support for the efficient development of tight gas reservoirs in the study area.

The shallow lithologic oil pool in Bohai Sea has the characteristics of thin target beds, rapid longitudinal and transverse change of sand body, complex sand body configuration, etc. Adopting the "stabilizing hole-deviation angle to explore the top of the target bed" method commonly used for thin reservoir geosteering often results in drilling through the target bed during landing, which brings great difficulties and challenges to the accurate landing of horizontal wells. By summarizing relevant data and analyzing and improving the applicability of conventional landing methods for horizontal wells, a low hole-deviation landing geosteering method for thin reservoir horizontal wells is proposed, that is, once the target layer is found by stabilizing hole-deviation angle, land immediately, and the remaining deflection section is implemented in the horizontal section. The successful application of this method in well H has confirmed that it effectively improves the landing success rate of thin reservoir horizontal well, and can provide reference for similar thin reservoir horizontal well landing geosteering.

The improvement and breakthrough of the exploration technology of buried hill oil-gas pool in marine exploration put forward higher requirements for mud logging in reservoir effectiveness evaluation, that is, the buried hill reservoir interpretation and evaluation are fine and quantified. The geological logging interpretation and evaluation of buried hill reservoirs also faces the problem of increasing the difficulty of qualitative evaluation due to the diversity of data. Currently, reservoir reliability assessment methods cannot achieve dimensionality reduction of multiple geological logging data.The fuzzy matter-element analysis method is used to conduct fusion evaluation of multiple parameters from gas logging, three-dimensional quantitative fluorescence logging, element logging, diffraction logging, etc., which can reduce the multidimensional to the one-dimensional and comprehensively evaluate the physical properties and oil-gas potential of the reservoirs. According to the mechanical specific energy and mechanical specific energy base values of engineering logging parameters, the vuggy-fracture index is introduced to characterize the physical properties of buried hill reservoirs. Finally, the standards of reservoir effectiveness are quantified by intersecting the comprehensive evaluation indicator of the fuzzy matter-element and the vuggy-fracture index, which provides a new method for reservoir effectiveness evaluation in buried hills. The application of this evaluation method in new drilling wells in a certain block has obtained good results.

Traditional geochemical pyrolysis technology has the problem of the easy loss of light components of hydrocarbons during the analysis process, resulting in the distortion of the geochemical pyrolysis parameter S₀, and the loss process of light hydrocarbons is affected by various factors. The current pyrolysis correction and restoration methods still cannot accurately restore the actual hydrocarbon content of the sample, which have constrained the accurate evaluation and application of traditional geochemical pyrolysis technology to shale oil mobility. In response to the above problems, a method of applying the four-temperature-step sealed pyrolysis logging technology to evaluating the mobility of shale oil in the Weixinan sag is proposed. The sum of S_g and S₀₁ values obtained by this method is defined as the S₀ of the four-temperature-step sealed pyrolysis,which is 35.7 times higher than the S₀ of on-site rock pyrolysis, and the gradient analysis of the full-component hydrocarbons is realized. Obtained from the four-temperature-step sealed pyrolysis and on-site pyrolysis TOC for the cored intervals of well WYX 1 of Weizhou X structure, the average oil saturation index （OSI） is 258 mg/g, the average gaseous hydrocarbon index is 0.085, and the average ratio of light hydrocarbon to heavy hydrocarbon ratio is 0.35, indicating that the shale oil in the study area has good mobility and potential for exploitation. The four-temperature-step sealed pyrolysis logging technology can effectively avoid the loss of light hydrocarbon, realize the accurate determination of gaseous hydrocarbon and free hydrocarbon content, reduce the real hydrocarbon content of shale, and provide a reliable method for evaluating the mobility of offshore shale oil.

With the deepening of exploration and development, the continuous increase in reserves and production of K oilfield in Bohai Sea has encountered a bottleneck, and low-resistivity oil layer has gradually become an important exploration target. However, the controlled factors of Guantao Formation in K oilfield of Bohai Sea are complicated and changeable, and the conventional mud logging and well logging evaluation methods cannot effectively and rapidly identify the low-resistivity reservoirs while drilling. For the reservoirs of Guantao Formation in K oilfield of Bohai Sea, by deeply mining the correlation of resistivity controlled factors, mud logging parameters, and hydrocarbon abundance, the characteristic parameters of gas logging, geochemical logging, and three-dimensional quantitative fluorescence logging were optimized. Combined with the resistivity, the multivariate parameter interpretation and evaluation method for formation fluid was established. This method can effectively identify the low-resistivity oil layers while drilling, increase the formation fluid interpretation coincidence rate to more than 88%, and provide an effective means for increasing reserves and production in K oilfield of Bohai Sea.

Mud logging technology evaluation is determined in this paper from 3 aspects to solve geological and engineering characteristics and technical difficulties in drilling and exploration process of compressed air energy storage injection-production wells. The evaluation method for halite, gypsum and mirabilite has been established by saturated brine experiment based on XRD & XRF technology. Based on comprehensive mud logging engineering parameters, the forecasting standards for abnormal engineering situation have been built with the combination of 5 stages in determining horizons of entering cavity of injection-production wells. Relying on geological data and combining with engineering requirements, the horizon determination method of compressed air energy storage injection-production wells has been set up. There are 18 abnormal situation alarms in the verification of 7 wells on the site, the accuracy rate is 100%, and the accuracy rate of finding the top of the salt cavity is 100% after midway completion, which fully verifies the effectiveness of the above evaluation methods, and provides reference methods and standards for the later drilling of compressed air energy storage injection-production wells.

The oil and gas resources in northern Shaanxi area of the Ordos Basin have the characteristics of wide distribution and are the key area of oil and gas exploration. The systematic scientific study of the accumulation time and accumulation period of the Chang 2 and Chang 6 reservoirs in the Zhidan area of northern Shaanxi is not only conducive to the fine exploration of the oilfield, but also improves the understanding of the Triassic oil and gas accumulation in the Ordos Basin. The characteristics of inclusions are observed under microscope and fluorescence, and the hydrocarbon accumulation period of the reservoir fluid inclusions is divided by the inclusion homogenization temperature experiment and freeze point experiment. The results show that there are three main types of inclusions of Chang 2 and Chang 6 reservoirs of Yanchang Formation in the Zhidan area of northern Shaanxi, namely brine inclusions, liquid-containing hydrocarbon inclusions and liquid hydrocarbon inclusions, and liquid hydrocarbon inclusions are mostly yellowish-green and orange-yellow under fluorescence irradiation, which indicates that the maturity of organic matter in the Chang 2 and Chang 6 reservoirs reaches a medium level. The fluid inclusions of the Chang 2 and Chang 6 reservoirs are mainly distributed in the quartz overgrowth and quartz healing microfissures, and the homogenization temperature distribution continuously indicates that the Chang 2 and Chang 6 reservoirs are one-stage charging. The homogenization temperature is mainly distributed the rage of 85-130 °C, the peak is the range of 90-110 °C, and the brine inclusions have the characteristics of high temperature, medium salinity and medium-high density, which are derived from the oil and gas fluids formed during the thermal evolution of organic matter, the accumulation time is during 111-100 Ma, and the accumulation time is the late Early Cretaceous.

The drilling fluid level in the buffer tank at the mud logging site often fluctuates up and down with the changes of pump displacement and bottom-hole complex situations, and the influence of some human factors. In order to stabilize degassing, the degasser needs to be manually regulated according to the changes of drilling fluid level. Otherwise, if the drilling fluid level is too high, it may cause the pumping drilling fluid to block the gas pipeline and burn the motor.If the drilling fluid level is too low to degas the drilling fluid, resulting in the loss of gas logging data. In order to save manpower and ensure the accuracy and timeliness of gas logging data, the full automatic level self-regulating degasser has been researched and developed, which can measure the level height through the ultrasonic liquid level sensor, then drive the motor to regulate the liquid intake height of the degasser up and down, and automatically deal with the complex situations such as level heave and excessive drilling fluid bubbles in the buffer tank. Compared with the traditional degassers, the full automatic level self-regulating degasser changes the regulation drive mode, realizes automatic regulation for the liquid intake height of the degasser, thereby reducing labor intensity, improving equipment operation reliability and inherent safety, and enhancing the quality of gas logging data.

The problems of little well data, poor seismic data quality, rapid lateral changes of reservoirs, and the large differences in reservoir thickness and structure between different vertical oil formations result in great difficulties in accurate prediction of dominant reservoirs in the early stage of offshore mid-deep hydrocarbon bearing pool development. The first member of Shahejie Formation in D oilfield of Bohai Sea is taken as an example to carry out analysis of the main controlling factors of reservoir distribution. The dominant reservoirs are predicted through palaeogeomorphology restoration, seismic attribute analysis and reservoir cluster analysis. The findings indicate that the early sedimentary reservoirs in D oilfield are controlled by palaeogeomorphology, with dominant reservoir development occurring in gully and slope belt. The middle sedimentary reservoirs are controlled by both palaeogeomorphology and provenance, with dominant reservoirs forming in high positions on the west side of well area 1. The late sedimentary reservoirs are affected by provenace, leading to dominant reservoir development mainly in the southeast block of well area 1. These research results have effectively guided the optimization of well locations and drilling implementation for the D oilfield development plan, achieving successful outcomes that can provide a reference for similar oilfields.