摘要
天然气储层产能评价是储层测井综合解释的重要环节。但是,目前采用的天然气储层含气饱和度不能有效表征天然气储层的含气性。为此,在分析含气饱和度在天然气储层产能评价中所存在局限性的基础上,基于天然气物质的量和理想气体状态方程,提出了相对气体摩尔量定量评价储层含气性的新参数,给出了该参数的确定方法,并对鄂尔多斯盆地苏里格气田致密砂岩气藏某井进行了测井评价及相对气体摩尔量参数计算,分析了该参数的应用效果。研究结果表明:①相对气体摩尔量参数受孔隙度、含气饱和度和孔隙压力及天然气压缩因子的共同控制,精确计算孔隙压力和天然气压缩因子是确定相对气体摩尔量参数的核心;②储层的含气饱和度与储层的产气能力并非一一对应,高含气饱和度储层不一定都能获得高产,而相对中等含气饱和度的储层也有可能获得高产;③相对气体摩尔量参数能够精确反映储层的绝对含气量,在储层含气级别识别方面有着较好的应用效果,其数值大小能够直接指示储层含气性的好坏。结论认为,该研究成果为天然气测井综合解释提供了一条新的思路。
Productivity evaluation of natural gas reservoirs is an important part of comprehensive reservoir logging interpretation. However, the currently adopted gas saturation cannot effectively characterize the gas-bearing property of natural gas reservoirs. In this paper, the limitations of gas saturation in the evaluation of natural gas reservoir productivity were analyzed. Then, based on the quantity of natural gas and the ideal gas state equation, a new parameter for quantitative evaluation of the gas-bearing property of reservoirs was proposed, i.e., relative molar volume of gas, and its determination method were provided. Finally, logging evaluation was carried out on a certain well in the tight sandstone gas reservoir of the Sulige Gas Field in the Ordos Basin. What’s more, its relative molar volume of gas was calculated, and the application effect was analyzed. And the following research results were obtained. First, the relative molar volume of gas is controlled jointly by porosity, saturation, pore pressure and natural gas compressibility factor, and the accurate calculation of pore pressure and natural gas compressibility factor is the core of determining the relative molar volume of gas. Second, there is no one- to-one corresponding relationship between the gas saturation of a reservoir and its gas-producing capacity. In some conditions, reservoirs with high gas saturation are not always productive. On the contrary, reservoirs with relatively moderate gas saturation may also be highly productive. Third, the relative molar volume of gas can precisely reflect the absolute gas content of a reservoir. In addition, its application in identifying the gas-bearing level of a reservoir is remarkable, and its value can directly indicate the gas-bearing property of a reservoir. In conclusion, the research results provide a new idea for the comprehensive interpretation of natural gas logging.
作者
王修朝
Wang Xiuchao(Geology Research Institute of CNPC Great Wall Drilling Company, Panjin, Liaoning 124010, China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2019年第3期32-37,共6页
Natural Gas Industry
基金
国家科技重大专项"页岩气工业化建产区评价与高产井主控因素研究"(编号:2017ZX05035-004-001)
关键词
天然气储集层
含气性
定量评价
相对气体摩尔量
孔隙压力
天然气压缩因子
天然气密度
含气饱和度
Natural gas reservoir
Gas-bearing property
Quantitative Evaluation
Relative molar volume of gas
Pore pressure
Gas compressibility factor
Natural gas density
Gas saturation
