塔河油田下奥陶统碳酸盐岩储层对比及储层剖面模型

塔河油田奥陶系储层为岩溶缝洞型的碳酸盐岩储层，缝洞储层的形成与古岩溶作用密切相关，风化壳期岩溶作用对储集空间的发育程度有明显的控制作用。不同的储集空间类型受控于不同的岩溶古地貌单元。裂缝性储层主要分布于风化壳型岩溶不发育地区，或褶皱和断裂构造较发育的变化强烈部位；裂缝-孔洞型储层的分布与古岩溶发育带和岩溶斜坡地区密切相关；裂缝-溶洞型储层其分布与裂缝及古岩溶发育带密切相关，常常是在古岩溶高地边缘或部分岩溶斜坡区，多位于多组构造线的交汇处及褶皱的轴部等。为进一步探讨研究区缝洞型碳酸盐岩储层的空间展布规律，根据暴露区淡水岩溶作用发育特点，依据碳酸盐岩储层的波阻抗响应特征、测井曲线、测试成果及开发动态资料，在恢复古岩溶地貌的基础上，对塔河油田（6区）的岩溶值得层进行了划分与对比。研究结果显示高产井多位于古岩溶地貌相对较高部位，而产量较少或没有出油气的井，则位于岩溶地貌相对较低部位。表明早期的古地貌形态对奥陶系碳酸盐岩溶蚀孔洞的发育具有明显的控制作用。岩溶储层的垂向发育和分布主要受碳酸盐岩古岩溶风化壳垂向分带性的影响，纵向上由风化壳顶面向下储层发育逐渐变差。以奥陶系古风化壳顶面为界，向下每60m为单位，对深度0-60m、60-120m、120-180m、180-240m岩溶储层的纵横向分布特征进行了分析，并建立了相应的储层剖面结构模型。

CORRELATION AND STRUCTURE MODEL OF CARBONATE RESERVOIRS IN TAHE OIL FIELD

The Ordovician reservoir of Tahe oil field is a carbonate reservoir of karst fissure cavity type. Its formation is closely related to the paleo-karstification which has a clear effect on growth rate of carbonate reservoirs?dimension during the development of paleo-residue. Reservoir dimensions are controlled by varied paleo-karst units. The fracture-type reservoirs mainly developed in relatively poorlydeveloped residue karst domains, or in strongly folded and faulted localities. The fissure-pore type reservoirs are closely associated with the paleo-karst or karst slope domains. The fissure cave type reservoirs are related to cracks or paleo-karst domains, usually at karst highland edges or paleoslopes, and at junctures of faults or cracks or fold axes. In order to understand the distribution of carbonate reservoirs, a correlation and division of karst reservoirs in Tahe oil field are conducted, by recovering paleokarst topography, based on karstification features of fresh water in exposure conditions, responses of wave impendence to carbonate rocks, log curve, test data and oil development data. It shows that the higher yield wells are mostly located in relatively higher position of paleokarst domains, and lower output or dry wells mostly in lower position of paleokarst domains. This implies that that the early stage of paleo-karst domains controls the development of solution caves of Ordovician carbonates. The vertical development and distribution of karst reservoirs are controlled by the vertical zonation of paleoresidues. The development of a reservoir gets weaker from top to bottom. The characteristics of both vertical and horizontal distribution of the reservoirs at intervals of 0~60 m, 60~120m, 120~180 m, 180~240 m beneath the exposed Ordovician surface are analyzed and the corresponding structural model is established.