考虑压力拱效应的苏里格气田上覆压力计算  

CALCULATION OF THE OVERBURDEN PRESSURE OF SULIGE GASFIELD CONSIDERING THE EFFECT OF THE STRESS CAMBER

作　　者：王钒潦[1] 李相方[1] 汪洋[2] 林孟鲁[1] 陈晓亮[1] 赵晶晶[3] 

机构地区：[1]中国石油大学石油工程教育部重点实验室,北京102249 [2]中海油能源发展股份有限公司,广东深圳518067 [3]中石化江苏油田分公司试采一厂,江苏扬州225264

出　　处：《大庆石油地质与开发》2013年第5期61-66,共6页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家重点基础研究发展计划("973"计划)项目(2007CB209506);(2009CB219606);国家科技重大专项课题(2011ZX05038-4)资助

摘　　要：目前所有的应力敏感实验都假设上覆压力不变,事实上,油气田开采时储层部分甚至整个上覆岩层的应力将重新分布,上覆压力将随着生产时间不断变化,因此计算不同形状储层上覆压力变化值对低渗储层应力敏感评价具有重要的意义。统计苏里格砂体展布特征,将储层模型简化为近饼状体模型和近椭圆柱体模型,以Sohanzadeh非均质理论为基础,计算了苏里格气田两种简化储层模型在油气开采时上覆压力的变化情况,并应用于储层的应力敏感评价中。结果表明:油气开采时,苏里格气田上覆岩层中形成压力拱,不同形状储层的压力拱比不同,近饼形储层和近椭圆柱体储层的最大压力拱比分别为0.276和0.119。地层压力降低30 MPa时,近饼状体储层上覆压力最大降低14%,近椭圆柱体储层上覆压力最大降低6%,对应的应力敏感渗透率较常规应力敏感实验分别提高38.57%和23.25%,对于压力拱效应显著的低渗储层,常规实验夸大了储层的应力敏感效应。All the stress sensitivity experiments suppose that the overburden pressure doesn＇t change. when developing the oil and gas fields, the stresses no matter of the reservoirs, parts of the reservoirs and the overburden rocks will distribute again, and moreover the overburden pressure will gradually change In fact, even all with the production time. Therefore there is important significance for calculating the changed values of the overburden pres- sures of different shapes of reservoirs in the evaluation of the stress sensitivity for the low-permeability reservoirs. By means of the statistics of the characteristics of the sandbody spread in Sulige Gasfield, the reservoir model is simpli- fied into penny-shaped and elliptic cylinder-shaped ones. On the basis of Sohanzadeh heterogeneity theory, the changes of the overburden pressures in the two simplified reservoir models are calculated when the petroleum is pro- duced and furthermore they are applied in the evaluation of the reservoir stress sensitivity. The results show that when the oil and gas are produced, the stress camber is generated in the overburden rocks of the gasfield, and mo- reover different shapes of the reservoirs have different stress arching ratios, the maximum ratios of the above two shapes reservoirs are 0. 28 and 0. 119 respectively. When the formation pressure drops by 30 MPa, the maximum dropped overburden pressure for the first shape of reservoirs reaches by 14% and the latter by 6%. For the stress- sensitivity permeability, the common stress sensitivity experiments are increased by 38.57% and 23.25%, respec- tively; for the low-permeability reservoirs with obvious stress camber effect, the common experiment has exaggerat- ed the stress sensitivity effect.

关 键 词：上覆压力 压力拱效应 压力拱比 非均质理论 应力敏感 

分 类 号：TE311.2[石油与天然气工程—油气田开发工程]