关键词: 地层压力, 测井数据, 孔隙度, 碳酸盐岩, 湖南保靖, 垂直有效应力

Abstract:

In the South China shale gas search, large sets of carbonate strata are often encountered.The formation pressure is closely related to shale gas enrichment, drilling and exploitation. In order to accurately evaluate the formation pressure of carbonate rocks, based on log information such as overburden pressure and porosity, and the principle of actual stress, mud logging put forward a method for evaluating formation pressure suitable for carbonate rocks, it overcomes the defects of traditional dc exponent formation pressure evaluation method which needs to establish the normal compaction trend line and is difficult to eliminate the lithologic influence. Through field test, the calculation precision of the formation pressure of this method is over 90%. It has the characteristics of real-time monitoring formation pressure and adapting to complex geologic environment, is able to calculate formation pressure directly, and can provide basis for selecting an area rich in shale gas and easy to exploit, well structure design and rational exploitation.

Key words: formation pressure, log data, porosity, carbonate rock, Baojing block in Hunan province, vertical actual stress