轮古西地区奥陶系碳酸盐岩储层特征研究

塔里木盆地轮古西地区奥陶系碳酸盐岩油气藏在很大程度上受岩溶型储层发育的控制，深入总结其储层特征及其控制因素，对油气勘探开发具有重要意义。为此从储层岩石学及储集性能等方面，对该区的奥陶系碳酸盐岩储层特征进行了阐述和分析，认为该区储层的基质孔渗极差，难以形成有利的储集空间，而次生孔隙（裂缝、溶蚀孔洞、洞穴等）构成了该区的主要储集空间，裂缝-孔洞型、洞穴型储集层较为发育，是最有勘探价值的储集层。通过对构造演化特征和岩溶系统的分析，认为储层的原生孔隙和沉积相带是次生孔隙形成的基础条件，构造运动产生的裂缝是促进岩溶发育、控制储集体发育的关键因素，岩溶作用是控制储层发育的主要因素。

FEATURES OF THE ORDOVICIAN CARBONATE RESERVOIRS IN LUNGUXI AREA

The Ordovician carbonate oil pools in Lunguxi area of the Tarim Basin are largely controlled by the development of karst reservoirs.A thorough study of the reservoir features and control factors is of great significance to petroleum exploration and development.This paper mainly describes and analyzes the features of the Ordovician carbonate reservoirs in the study area in respects of reservoir lithology and storage capacity.It is believed that the matrix porosity and permeability of the reservoirs in the study area are too low to form favorable reservoir spaces,while the secondary pores,fractures,dissolution cavities and vugs constitute the main reservoir spaces in this area.The fractured-vuggy and cavity reservoirs are well developed,thus are the most valuable exploration targets.Based on analysis of the characteristics of tectonic evolution and karst system,it is concluded that the primary pores and sedimentary facies belts are the basis for the formation of secondary pores,the fractures resulted from tectonic movement are the key factors enhancing karst development and controlling reservoir development,and karstification is the major factor controlling the development of the reservoirs.