碳酸盐岩缝洞型油藏缝洞单元形成机制及模式研究进展报告

金强 邹胜章 钟建华 田飞 康逊

摘 要：该研究以塔河油田4、6和7区缝洞储层为研究对象，对塔河油田缝洞型储层的成因结构和充填模式进行地质分析，建立塔河油田缝洞储层的结构模式和充填模式；研究其缝洞单元内储集空间的分布规律；通过多种地质因素综合研究，分析研究区奥陶系缝洞单元内储集空间的成因和主控因素。研究者建立了塔河油田缝洞储层的三维立体结构模式，明确了表层带、渗流带和径流带缝洞结构和充填模式。表层岩溶带主要由地表河、落水洞、断层及裂缝、坡积物和奥陶系裸露岩石所组成。根据现代岩溶和古岩溶的考察，以及塔河油田的井下资料解释，地表河和落水洞为河流沉积物和垮塌角砾岩充填。渗流岩溶带的缝洞主要由渗流井和驻水洞以及缝洞复合体组成。渗流井是连通表层岩溶带与径流岩溶带的水流通道，一般沿断层或裂缝发育渗流井废弃后常常被表层碎屑物或垮塌角砾充填，而驻水洞如果不受垮塌影响，则充填程度一般比较低，是非常好的油气成藏和产出空间。径流带内水流以横向流动为主，潜水面是径流带的底界。地下河溶洞是径流带缝洞的主要类型，在塔河油田根据地下河溶洞相互连通关系和规模，可以划分出干流洞、支流洞和末梢洞。在断层附近、地表落水洞下方可以形成规模巨大的厅堂洞。径流带溶洞大都具有比较强烈充填作用：地下河沉积碎屑充填，垮塌角砾充填和碳酸钙化学充填。针对表层带地表河和径流带溶洞系统沉积物岩性和沉积水动力条件进行研究，初步阐明了表层带和径流带不同成因结构水动力条件与沉积物物源。以南方和塔北古岩溶缝洞系统发育与充填特征研究，建立了洞穴垮塌机制与控制因素。裸露期岩溶洞穴垮塌和埋藏期岩溶垮塌成因机理差异明显。研究者基于不同充填物分别进行物性评价的思路，形成了缝洞充填物类型约束下多参数配合的物性评价方法。针对不同类型的缝洞充填物采用多参数组合法分别计算物性，建立不同缝洞充填物的物性评价方程，并与取心井实测孔隙度和渗透率进行对比分析。实践证明，与岩心实测物性对比符合率高，有效评价了研究区缝洞储集性能。

关键词：缝洞成因结构 充填模式 沉积机制 垮塌机制 物性评价 储集空间

Carbonate Fractured-cavity Reservoir Unit Formation Mechanism and Model Research

Jin Qiang1 Zou Shengzhang2 Zhong Jianhua1 Tian Fei1 Kang Xun1

（1.China University of Petroleum-East China；2.Institute of Karst Geology， Chinese Academy of Geological Sciences）

Abstract：This topic takes fracture-cavity reservoir as the research object in Tahe Oilfield NO.4， 6， and 7 zone to analyze geological structure and filling pattern， to establish the structure of the fracture-cavity reservoir in Tahe Oilfield mode and filling mode； Study the distribution rule of reservoir space inside fracture-cavity unit； Through a variety of geologic factors comprehensive research and analysis of the Ordovician in the study area. Researchers fracture-cavity reservoir in Tahe oil field is established three-dimensional structure model， has been clear about the surface， seepage flow and runoff with fracture-cavity structure and filling patterns.Runoff water is given priority to with transverse flow， groundwater level is runoff zone at the bottom of the world. Underground river water-eroded cave is the main type， the run-off zone fracture-cavity in Tahe Oilfield according to the underground river water-eroded cave and scale interconnected relations， can be divided into main tributaries hole， hole and peripheral hole. Near the fault， surface sink below can form a huge hall hole. Runoff belt cave has relatively strong filling： mostly underground river sedimentary clastic filling， collapse breccia filling and chemical filling calcium carbonate. On the surface with the surface of the river sediment and runoff belt cave system lithology and sedimentary hydrodynamic conditions， a preliminary illuminates the surface with different genetic structure belt and runoff hydrodynamic conditions and sediment source. System development in the southern and northern ancient karst fracture-cavity and filling characteristics research， cave collapse mechanism and control factors is established. Stage nudity karst cave collapsed and buried karst collapse formation mechanism difference is obvious.Researchers， property evaluation based on different fillings， respectively， to form the stitch holes fillings type constraints under multiple parameter with property evaluation methods. For different types of stitch holes fillings multi parameter set legal properties are calculated respectively， set up different property evaluation equation of stitch holes fillings， and coring Wells with the measured porosity and permeability were analyzed. Practice has proved that compared with core properties measured coincidence rate is high.

Key Words：Fracture-cavity formation structures；Filling pattern；Deposition mechanism；Collapsing mechanism；Property evaluation； Reservoir space

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