标题:
东海陆架盆地西湖凹陷气测录井半定量评价研究Semi-Quantitative Evaluation of Reservoirs with Gas Logging Data in Xihu Sag of East China Sea Shelf Basin
作者:
李泽超, 鲁法伟, 王雷
关键字:
西湖凹陷, 气测录井, 脱气效率, 地层含气量, 地层含气饱和度Xihu Sag, Gas Logging, Degassing Efficiency, Gas Content in Formation, Gas Saturation in Formation
期刊名称:
《Journal of Oil and Gas Technology》, Vol.39 No.4, 2017-08-15
摘要:
西湖凹陷目前已发现的储层主要集中在平湖组和花港组，属于低孔低渗储层，流体性质复杂，使用常规测井手段难以准确识别低孔低渗复杂油气层。气体解释的优点在于它不依赖于地层水、岩石骨架、泥质含量、矿物含量等参数，所以在低阻、低孔、低渗的“三低”储层，未知矿化度储层流体解释方面应用效果好。特别是在复杂油气层的识别方面对测井解释是一个补充。研究主要根据钻井液脱气试验和脱出气体的色谱分析，获取现场脱气仪的脱气效率，通过脱气效率分析获取钻井液含气量；结合钻时、排量、井径数据可转化为地层真实含气量。结合岩心、测井孔隙度等实钻数据，通过地下真实含气量与气体状态方程换算成地层含气饱和度。
The reservoirs discovered in Xihu Sag were mainly concentrated in Pinghu Formation and Hua-gang Formation, which were low porosity and permeability with complex fluid properties, and thus it was difficult for accurately identifying with conventional logging methods. The advantage of gas interpretation was that it was not based on the parameters as formation water, rock frame, mud content and mineral content, therefore it worked well in interpreting fluid with unknown salinity in low resistance, low porosity and low permeability reservoirs. It was a supplement for logging interpretation especially in the identification of complex hydrocarbon reservoirs. In this study, the degassing efficiency was obtained from mud degassing experiment and gas chromatographic analysis, and the gas content of the mud was determined through degassing efficiency analysis, then it was converted to real gas content of the formation based on the data of drilling time, displacement and borehole diameter. Combined with the core, logging, porosity and other real drilling data, the formation gas saturation is obtained from underground real gas content and gas state equation.