多层非均匀径向复合储层压力动态特征  

Pressure Dynamic Feature of Multi-layer Non-uniform Radial Composite Reservoir

作　　者：高敏 段蕾 史文洋 颜家伟 陆科杰 Gao Min;Duan Lei;Shi Wenyang;Yan Jiawei;Lu Kejie(No.4 Oil Production Plant PCOC, Yinchuan, Ningxia 750006, China;State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China;No.3 Oil Production Plant PCOC, Yinchuan, Ningxia 750006, China;CNOOC Energy Technology & Services Limited Drilling & Production Branch, Tianjin 300452, China)

机构地区：[1]中国石油股份有限公司长庆油田分公司第四采油厂,宁夏银川750006 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国石油股份有限公司长庆油田分公司第三采油厂,宁夏银川750006 [4]中海油能源发展股份有限公司工程技术分公司,天津300452

出　　处：《非常规油气》2020年第6期41-48,共8页Unconventional Oil & Gas

基　　金：“十三五”国家科技重大专项“复杂结构井丛式井井网及产能设计研究”(2017ZX05009-003)资助。

摘　　要：层状储层模型和复合储层模型是描述复杂储层非均质性的经典模型,为了研究多层复合储层的压力响应特征,建立了考虑纵向非均匀径向复合的多层复合储层渗流模型。利用拉氏变换和数值反演方法得到了多层非均匀径向复合储层的井底压力解,通过井底压力和压力导数曲线形态特征划分了流动阶段,进而分析了储层层数和纵向非均匀复合半径对井底压力响应的影响规律。研究发现①利用内外区径向流阶段的压力导数值可以识别参与渗流的层数;②在纵向均质的储层中,非均匀复合半径对井底压力响应的影响具有对称性、有界性、中值性;③中值半径比均值半径替代非均匀复合半径引起的误差小,中值半径可以通过等效渗流体积得到;④均值半径不一定等于中值半径,慎重使用均值半径代替非均匀复合半径。结论认为等效渗流体积可以解释试井的多解性,等效中值半径能够解释非均匀复合储层的压力响应,但不能够精细地描述储层的纵向局部特征。Layered reservoir model and composite reservoir model are classical models for describing heterogeneity of complex reservoirs.To capture the pressure response characteristics of multi-layer composite reservoirs,a multi-layer composite reservoir seepage model considering vertically non-uniform radial composition had been established.The bottom hole pressure solution of multi-layer non-uniform radial composite reservoir was obtained by Laplace transform and numerical inversion method.The flow regimes were divided by the characteristics of pressure and pressure derivative curve.The influences of layer number and vertical non-uniform composite radius on pressure response were analyzed.And the following research results were obtained.First,the number of reservoir layers involved in seepage can be identified by the pressure derivatives value of the inner and outer radial flow regime.Second,when the reservoir is vertically homogeneous,the effect of the non-uniform composite radius on the pressure response is symmetrical,bounded,and replaceable.Third,the error caused by the median radius instead of the non-uniform composite radius is less than that caused by the mean radius,and the median radius can be obtained by the equivalent seepage volume.Fourth,it is not rigorous to replace the non-uniform composite radius with the mean radius,because the mean radius is not necessarily equal to the median radius.It is concluded that the equivalent seepage volume can explain the multi-solution of well testing.Median radius can explain the pressure response of multi-layer non-uniform composite reservoir,but it cannot describe the local characteristics of reservoir precisely.

关 键 词：层状储层 复合储层 纵向非均质 多层径向复合 压力动态特征 

分 类 号：TE121.1[石油与天然气工程—油气勘探]