白音查干凹陷桑合地区腾格尔组储层特征及主控因素分析

白音查干凹陷桑合地区腾格尔组碎屑岩储层岩性主要为长石砂岩、岩屑长石砂岩和长石岩屑砂岩，填隙物以钙质胶结物为主，孔隙式胶结。储集空间类型主要为原生孔隙，以点状、片状喉道为主，具有喉道半径差别大，分选差，孔隙连通性差等孔隙结构特征。沉积环境及成岩作用为该区储层发育的主控因素。扇三角洲平原和前缘过渡带为有利储层发育区。压实及胶结作用通过减小孔隙空间及填充喉道对储层起破坏性作用；溶蚀作用则通过形成次生溶孔对储层起建设性作用。纵向上，发育两个储层物性异常带；平面上，扇三角洲平原与前缘相的过渡带为近物源、多物源、快速堆积模式，压实作用占主导地位，沉积相带与成岩相带共同作用形成平衡带。多种控制因素的综合效应，是该平衡带储层物性变好的主要原因。

Characteristics and Main Controlling Factors of Tenggeer Formation Reservoir in Sanghe Area, Baiyinchagan Sag

Reservoir rocks of Tenggeer Formation in Shanghe area of Baiyinchagan Sag, mainly consists of arkose , lithic arkose and feldspathic litharenite. The main interstitial matter is carbonate, basically comprised by calcite and dolomite. Cementation type is pore cementation. The primary intergranular pores are the main reservoir spaces.The pore structure is characterized by small pore throat radius,poor connection and poor sorting.The reservoir porosity and permeability has a good positive correlation and the reservoir permeability is mainly controlled by the pore abundance.
  The primary controlling factors of reservoirs in this area are sedimentary environment,burial depth and diagenesis.Sedimentary facies, clastic particle's physical property and differences of diagenetic minerals significantly controlled the physical properties of reservoirs. The component of diagenetic minerals are influenced by the sedimentary facies and the lithology at provenance. The 1 600 1 900 m well section shows abnormal lower value of physical properties with the plastic minerals such as debris and feldspar significantly increased. Burial depth in this area also have some control effect on physical properties. Generally, reservoir physical properties becomes poor with the increasing of burial depth. In addition, diagenesis have exerted great effects on the proporties of reservoir rocks. The most destructive diagenesis is compaction,  it is one of major affecting factors for poor reservoir physical properties in the study area. Compaction and cementation are the main pore destroyers,  which reduce the pore space and block pore throat. Dissolution play a constructive role in forming secondary solution pores,  it obviously improved the reservoir properties. In 2 000 2 200 m range, it developed a dissolution zone. In this zone, the reservoir physical properties become better.
 Transitional area of fan delta plain and fan delta front is the favorable zone in the study area. The transitional zone is a balance area with the joint influence of depositional facies, burial depth and diagenesis. This balance area tends to have the features of proximal  provenance and multiple origins with rapidly deposited sediments, where compaction is the dominate diagenesis. The reservoir physical properties in this balance area is controlled by many factors,  and its favorable physical properties is the contribution of their comprehensive effects.