塔里木盆地天山南地区古近系储层特征及其控制因素

Study on Paleogene reservoir features and controlling factors,south Tianshan area,Tarim basin

根据钻井、测井与分析测试资料，对塔里木盆地天山南地区古近系储层特征及其控制因素进行了研究。天山南地区古近系岩石类型以长石石英砂岩和岩屑长石砂岩为主，铁泥质、钙质和石膏等填隙物含量高，分选、磨圆中等，具有成分成熟度高、结构成熟度中等的特点。砂岩储层孔隙类型主要有粒间孔、粒间溶孔、粒内溶孔、微孔及裂缝等，其中以溶蚀孔隙为主，粒间孔次之。孔隙度主要为4．5％～17．5％，渗透率为0．1×10^-3～10×10^-3μm2，总体属于细孔喉的特低孔一特低渗透储层。影响研究区储层物性的主要因素有沉积相和成岩作用等，其中辫状河三角洲前缘的分流河道和席状砂储层物性好，是有利的油气储集相带，胶结作用和溶蚀作用是影响天山南地区古近系储层发育的最主要成岩作用。

The reservoir characteristics and major controlling factors of reservoir quality of the Paleogene in the southern Tarim basin are analyzed by means of massive drilling data,well logging and test data.This study shows that the reservoir of the Paleogene in the study area shows high compositional maturity and middle textural maturity,which has the characteristics that the main lithologies of the reservoir are feldspar quartz sandstone and lithic arkose,the high matrix contents and medium roundness and sorting.Types of pores of the sandstone reservoir are mainly intergranular pores,dissolved pores between grains,intragranular dissolved pores,all kinds of microporous and cracks and so on.Denudation pore is the major type,and then intergranular pore.The reservoirs are extra low porosity and permeability with the porosity ranging from 4.5% to 17.5% and permeability ranging from 0.1×10-3μm2 to 10×10-3μm2.The reservoir in research area is mainly affected by combined factors of depositional environment and diagenesis.The main diagenesis types are cementation and dissolution.By comprehensive analysis,the result shows that the favorable reservoir is mainly distributed in sheet sand and underwater distributary channel.