彩25井区储层基本地质特征及储层伤害因素分析  

ANALYSIS OF THE GEOLOGIC CHARACTERISTICS AND DAMAGE FACTORS IN RESERVOIR OF CAI 25 WELL BLOCK

作　　者：董悦[1] 衣德强[1] 李天太[1] 徐玉林[2] 胡金伟[3] 

机构地区：[1]西安石油大学石油工程学院,710065 [2]长庆石油勘探局采油三处 [3]长庆石油勘探局钻宇集团

出　　处：《钻采工艺》2008年第3期47-50,共4页Drilling & Production Technology

基　　金：国家自然科学基金资助项目,项目名称是“泥页岩井壁稳定力学与化学耦合机理研究”,编号:90610012。

摘　　要：彩25井区火山岩储层主要以安山质火山岩为主，夹有部分玄武岩。火山岩储层中存在有大量的原生铁镁矿物，同时火山岩的蚀变又形成了大量的敏感性矿物，这些矿物是造成储层酸敏、碱敏、水敏、速敏和微粒运移等伤害的主要因素。而强烈的迭敏、酸敏和水敏可能导致黏土矿物的解体，从而造成微粒运移，堵塞孔喉，使渗透率降低，伤害储层。此外还有少量的伊蒙混层矿物和片状伊利石，它们也是造成储层伤害的主要因素。火山岩储层属于小孔、低敏感性和低渗透率的储层，一旦造成伤害，很难恢复其原始渗透率。储层岩石中稳定组分长石和石英含量偏低，而不稳定组分岩屑含量很高，岩屑以泥岩岩屑、火山岩岩屑和变质岩岩屑为主。这些岩屑是储层出现各种敏感的一个主要因素。矿物胶结物主要为方解石，在岩石中分布比较均匀，它们强烈交代碎屑矿物，又是储层发生酸敏的主要原因。碎屑岩储层平均孔径在40～50μm，孔喉配位数低。孔隙类型主要以粒间孔为主、粒间溶孔为次，喉道细小，所以由于以上原因而形成的储层伤害，在此类储层中很难恢复。The reservoir of Cai25 well block is mainly composed of volcanics and partly basalt. It contains lots of primary iron and magnesium mineral. At the same time, the alteration of volcanics forms lots of sensitive minerals. These minerals may cause some damage like acid sensitive, alkaloid sensitive, water sensitive, velocity sensitive, corpuscle movement and so on. Intensive velocity sensitive, acid sensitive and water sensitive may lead to the clay mineral cracking, so the corpuscle movement, pore throat jam, permeability reduction will result in reservoir damage.Moreover a little andreattite mixed layer and sheet illite also are the main damage factor to reservoir.The volcanic reservoir belongs to tiny pore, low sensitivity and low permeability reservoir. It is difficult to refresh its native permeability once upon damaged. The contents of stable components liked feldspar and silex are lower, and the unsteady components liked cuttings which are main mudstone cuttings, volcanic cuttings and metamorphics cuttings are higher in the reservoir. These cuttings are chiefly elements to create reservoir sensitivity. Calcite is the main cementing materials which are uniformly distributed in the rocks. The strong metasomasis of them is another main reason of reservoir acid sensitive.The average bore diameter of clasolite reservoir is 40-50μm. The coordinate number between hole and throat is small. The types of pore are firstly intergranular pore, and, secondly the intergranular dissolved pore with fine throat, so the damage caused by the above reasons is hard to retrieve in this reservoir.

关 键 词：储层 伤害因素 地质特征 实验分析 

分 类 号：P618.13[天文地球—矿床学]