摘要
砂岩储层在关键成藏期以后仍然经历了一个较长时间的成岩作用,储层性质一直在发生变化,属于一个“动态演化”过程,利用现今储层物性去评价成藏期储层含油气性,其效果往往不太理想。针对上述问题,以鄂尔多斯盆地北缘杭锦旗地区独贵加汗区带致密砂岩气储层为例,从油气成藏动态角度出发,结合分析测试、测井解释、试气成果等多种地质资料确定了致密砂岩储层现今含气物性下限,然后利用盆地模拟和孔隙度埋深回推等方法恢复了储层成藏期后孔隙度变化增量,从而确定了致密砂岩气成藏期储层的临界物性下限,通过古孔隙度恢复方法分析储层在成藏期是否为有效储层,并进一步利用过剩孔隙度评价了砂岩储层的含油气性。研究结果表明:(1)研究区盒1段现今储层含气孔隙度下限为4.25%,储层成藏期后孔隙度变化增量平均值为3.1%,储层成藏期临界孔隙度为7.35%;(2)通过古孔隙度演化定量恢复方法确定盒1段砂岩储层在成藏期孔隙度基本大于成藏期储层临界孔隙度,判定砂岩储层在成藏期具有较好的横向输导天然气的能力;(3)过剩孔隙度与天然气日产量具有更好的相关性,揭示了利用过剩孔隙度评价致密砂岩储层含油气性是有效的。综合确定砂岩储层成藏期临界物性以及运用过剩孔隙度评价储层含油气性的方法对非常规油气储层评价具有重要的指导及借鉴意义。
The sandstone reservoir still experienced a long time of diagenesis after the key accumulation period,and the reservoir properties have been changing,which belongs to a“dynamic evolution”process.It is often not ideal to evaluate the oil and gas properties of the reservoir in the accumulation period by using the present reser⁃voir physical properties.In view of the above problems,taking the tight sandstone gas reservoir of the first mem⁃ber of Shihezi Formation(He 1 Member)of Lower Permian in Hangjinqi area,northern Ordos Basin as an ex⁃ample,the lower limit of current gas bearing property of tight sandstone reservoir was determined from the per⁃spective of oil and gas accumulation dynamics and combined with various geological data such as analysis,test⁃ing,logging interpretation and gas test results.Then the basin simulation and the porosity depth push back are used to recover the increment of porosity change after the reservoir accumulation period,so as to determine the critical physical property lower limit of tight sandstone gas accumulation period.The paleo-porosity recovery method is used to analyze whether the reservoir is an effective reservoir in the accumulation period,and the ex⁃cess porosity is further used to evaluate the oil and gas properties of the sandstone reservoir.The results show that:(1)The lower limit of gas-bearing porosity of the He 1 Member in the study area is 4.25%,the average increment of porosity after reservoir accumulation period is 3.1%,and the critical porosity during reservoir accu⁃mulation period is 7.35%.(2)Through the quantitative restoration method of paleo-porosity evolution,it is de⁃termined that most of the sandstone reservoirs in the He 1 Member have not reached the critical porosity of res⁃ervoir formation period,and the sandstone reservoir as a whole still has a good lateral transport capacity.(3)There is a better correlation between excess porosity and daily natural gas production,which reveals that it is ef⁃fective to use excess porosity to evaluate the oil and gas properties of tight sandstone reservoirs.Therefore,the comprehensive determination of critical physical properties of sandstone reservoirs during reservoir formation and the application of excess porosity to evaluate reservoir oil-bearing properties have important guidance and reference significance for unconventional oil and gas reservoir evaluation.
作者
赵振
刘震
何发岐
张威
安川
贺银军
朱茂林
艾席扬
ZHAO Zhen;LIU Zhen;HE Faqi;ZHANG Wei;AN Chuan;HE Yinjun;ZHU Maolin;AI Xiyang(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;College of Geosciences,China University of Petroleum,Beijing 102249,China;SINOPEC North China Company,Zhengzhou 450006,China;CNOOC Experimental Center,CNOOC EnerTech-Drilling&Production Co.,Tianjin 300452,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2024年第3期449-464,共16页
Natural Gas Geoscience
基金
国家自然科学基金“沉积盆地埋藏过程对砂岩压实程度的控制作用研究”(编号:41672124)
国家科技重大专项“致密气成藏机理与富集规律研究”(编号:2016ZX05047001-002-002)联合资助。
关键词
致密砂岩储层
临界物性
过剩孔隙度
盒1段
杭锦旗地区
Tight sandstone reservoir
Critical physical property
Excess porosity
He 1 Member
Hangjinqi area
作者简介
赵振(1993-),男,蒙古族,内蒙古呼伦贝尔人,博士研究生,主要从事石油地质学基础及应用研究.E-mail:zhaozhenlm@163.com;通信作者:刘震(1963-),男,陕西长安人,博士,教授,博士生导师,主要从事石油地质学基础及应用研究.E-mail:liuzhenjr@163.com.
