初论碳酸盐岩网络状油气藏──以塔里木盆地轮南奥陶系潜山油气藏为例

A primary discussion on the network-like oil and gas pools in carbonate rocks-Taking the Lunnan Ordovician buried-hill pool in Tarim basin as an example

网络状储集空间由被裂缝系统串联起来的孔洞系统构成，多发育在碳酸盐岩之中，所形成的油气藏形态的不规则性和结构的非均质性以及隐蔽性很强，在油气藏形态分类和勘探中，都应作为一种独立的基本类型。提出将其归入不规则油气藏大类，作为与透镜状油气藏并列的单独类型，命名为“网络状油气藏”。概念是：以孔洞-裂缝系统为储渗空间，以四周致密岩层封闭为遮挡条件，形成的彼此独立的网络状不规则油气聚集。以塔里木盆地轮南地区和四川盆地川南的网络状油气藏为例，论述其主要特征是储集空间为多个孔洞-裂缝系统，因而网络状含油储渗体系基本互不连通。勘探这类油气藏要特别重视研究岩溶发育及破裂改造的强度。轮南地区奥陶系潜山的勘探实践表明，评价网络状油气藏并预测其分布，必须采用地质、物探密切结合和多学科综合的技术与方法；在发现了商业性油气流井后，首先进行试采，认识稳产条件，再结合测试数据初步估计含油气范围，用压降法预测该井的可采储量，同时在地质条件相似处进一步钻探、试采，扩大储量，建成产能。对网络状油气藏形成与分布规律的认识和勘探技术的应用，都还有待于进一步完善。图4表2参8（王孝陵摘）

The network-like space of the reservoir made up of pores and vugs linked by fracture system, often exists in the carbonate rocks.The shape and the configuration of this type of pool is irregular,heterogeneous and well concealed, which should be classified as an independent basic type. It is proposed that this pool belongs to irregular one, paralleling to lens-like pool, and can be named 'network-like pool'. The definition of this kind of pool is as follows: an independent netwok-like irregular petroleum accumulation which possesses reservoir space of pore fracture system and is closed by boundary tight rocks. According to the examples of Lunnan area in Tarim basin and the southern area of Sichuan basin,the major feature of this kind of pool lies in the multi-pore-fracturesystems, and the netwok-like fluid systems are not interconnected.Exploring such reservoirs needs paying much attention to the intensity of karst and fracture. The exploration of Ordovician buried hill in Lunnan area shows that the evaluation and forecastingof netwok-like reservoir needs a close integration of geological and goophysical technologies and ways. And after the discovery of commercial petroleum, test production should be taken first in order to identify the conditiom for production stabilization. Combining the test data, the petroleum-bearing area can be elementarily estimated. The recoverable raserves can be forecasted by the method of praseure decline. The further drilling and test production can be proceded in the area with similar geology conditions, then the reserves can be enlarged and the production capacity achieved.The understanding to the forming and distribution of network-like petroleum accumulation and the application of this exploration technique need further consummated.