油水比例变化对岩石力学性质的影响及出砂分析——以金湖凹陷秦营断块区阜宁组储层为例  

Influence of change in oil-water ratio on rock mechanical properties and sand production analysis: A case study on Funing formation reservoir of Qinying fault block area in Jinhu sag

作　　者：孙珂 陈清华[1] 徐珂 孙建芳[3] SUN Ke;CHEN Qinghua;XU Ke;SUN Jianfang(School of Geosciences,China University of Petroleum,Qingdao,Shandong 266580,China;PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000,China;SINOPEC Petroleum Exploration and Production Research Institute,Beijing 100083,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国石油塔里木油田公司,新疆库尔勒841000 [3]中国石化石油勘探开发研究院,北京100083

出　　处：《中国矿业大学学报》2021年第5期909-922,共14页Journal of China University of Mining & Technology

基　　金：国家科技重大专项(2016ZX05006-003-002,2016ZX05014-002);中国博士后科学基金项目(2019M660269)。

摘　　要：为明确储层岩石力学性质在油藏注水开发中的变化及对油井出砂的影响,以金湖凹陷秦营断块区阜宁组储层为例,通过岩石力学试验和测井资料计算,在分析油水比例变化对岩石力学性质影响规律的基础上,探讨了其影响机制,并将研究成果应用于出砂风险分析。开展不同围压、不同流体条件下的岩石压缩试验,厘清了砂岩储层岩石力学参数的定量变化规律;基于测井资料,计算了不同岩石力学参数条件下地应力、油井临界生产压差、出砂指数,认为岩石力学性质随油水比例降低而逐渐弱化,而岩石力学性质的弱化降低了临界生产压差,从而增大了油井出砂风险.研究结果表明:地层水对岩石力学性质的弱化程度高于石油,导致随含水饱和度升高,岩石抗压强度和弹性模量逐渐降低,最高降幅分别达42.96%和28.18%;围压升高一定程度上减小了含水饱和度升高对岩石力学性质的弱化程度,影响幅度在16.78%以内;孔隙流体作用下砂岩储层的孔隙度及初裂强度降低、毛细管力减小以及黏土矿物溶胀等因素是造成岩石强度降低的主要原因;油藏注水开发中含水饱和度升高使油井出砂风险指数增高,建议合理控制生产压差并实时监测地层压力和生产压力.The Funing formation reservoir in the Qinying fault block area in Jinhu sag was researched as the target interval to determine the changes of reservoir rock mechanical properties caused by the oil-water ratio and its impact on the sand production from oil wells during the water injection development of the reservoir. Through rock mechanics test and logging data calculation, the influence of oil-water ratio on rock mechanical properties was analyzed, and then the influence mechanism was discussed. The research results were applied to the analysis of sand production risk. Through the rock compression experiments under different confining pressures and fluid conditions, the changes of rock mechanics parameters were quantitatively clarified. Furthermore, the in-situ stress, critical production pressure and sand production index under different rock mechanics parameters were calculated based on logging data. It was suggested that the rock mechanical properties were significantly weakened during the changes of oil-water ratio, which induced the decrease of critical production pressure difference and the increase of sand production risk in oil wells. The results showed that formation water weakened the mechanical properties of rocks to a greater extent than petroleum did, which induced the gradually decrease of rock compressive strength and elastic modulus with the increase of water saturation, with the largest decreasing amplitude reaching 42.96% and 28.18%, respectively. The increase of confining pressure reduced the weakening extent of rock mechanical properties which was caused by the increase of water saturation, and the influence amplitude was within 16.78%. Under the condition of fluid in pores, the decrease of porosity and initial crack strength, the decline of capillary force, and the swelling of clay minerals were the main factors causing the decrease of rock mechanical properties. As the water saturation increased, the sand production risk increased during the water injection development of reservoir. Hence,

关 键 词：油水比例 砂岩储层 岩石力学性质 影响机制 出砂分析 

分 类 号：TE122.1[石油与天然气工程—油气勘探]