塔北隆起南坡奥陶系油气藏类型辨析

Differentiation and Analysis of Ordovician Reservoir Types in South Slope of Tabei Uplift,Tarim Basin.

中国海相油气田都经历了多期成藏和后期改造,它们既不是典型的原生,也与海生陆储的次生油气藏有明显的区别,它应属准原生油气藏。对以碳酸盐岩中不规则的岩溶洞缝体来说,不宜再用储集层和盖层的称谓,而应采用储集体和封堵体的概念。不规则储集体分纳溪型、塔河型、任丘型三大类,其岩溶缝洞的发育程度和孤立储集体间的连通程度依次加强,其中的流动性质、油气水界面和压力的统一性也随之增强。塔河油藏既不是层状、块状,也不是地层不整合、风化壳型油藏,而是网络状油藏,其内部的油气水性质、界面位置、压力均有较大差别。阿克库勒凸起和塔河油区都是多类型储集体的组合。该隆起具有整体含油性和巨大的含油不均一性。测试和试采是评价该类储集层的主要手段,酸压改造是勘探开发中“常规性”的程序。

The marine oil-gas fields have undergone multistage petroleum accumulations and post-reconstructions.They should belong to quasi primary reservoirs for they are not typical primary reservoirs and clearly different from secondary reservoirs with marine-source and continental reservoir in nature.Therefore,carbonate rocks with irregular karst and fissure-cavity won't be named as reservoir rock or caprock rather than as reservoir body or sealing system.The ir regular reservoir body can be divided into Naxi type,Tahe type and Renqiu type,in which developed extent of karst and fissure-cavity as well as connected degree between isolated reservoir bodies are in increase in order,in-cluding flow property,oil-gas-water contact and universal pressure system.Tahe reservoir is neither stratified and blocky,nor stratigraphic unconformity and weathered crust reservoirs.It is network-like reservoir in which oil-gas-water property,con tact and pressure appear in obvi-ous difference.There exist assemblages of multi-type reservoir bodies in Ackule salient and Tahe area.This uplift is of macro petroliferous property and inhomogenous feature.Well test and production test are main tools for evaluation of this type of reservoir,while acid fracturing deconstruction is a“conventional”procedure in the exploration and development.