山东车西洼陷异常高压对特低渗储层的影响  

Influences of abnormal overpressure on super-low permeability reservoirs in Chexi depression in Shangdong

作　　者：马晓鸣[1] 赵振宇[2] 刘昊伟[2] 

机构地区：[1]中国地质大学能源学院,北京100083 [2]中国石油勘探开发研究院鄂尔多斯分院,北京100083

出　　处：《中南大学学报（自然科学版）》2011年第8期2507-2513,共7页Journal of Central South University:Science and Technology

基　　金：中国石油科技创新基金资助项目(2010D-5006-0104)

摘　　要：山东无棣县车西洼陷沙四上亚段碎屑岩储层以含泥细砂岩为主,孔隙度多集中在10%～20%,渗透率多小于10×10-3μm2,综合评价为中-低孔特低渗较差储层。研究区北部三角洲前缘及半深湖亚相存在异常高压,压力系数为1.2～1.5。研究结果表明:异常高压的形成主要与地层不均衡压实有关,其次矿物成岩作用有助于超压的保存与提高;异常高压有效抑制了地层温度的增加和成岩作用的加深;异常高压有效减缓了地层压实作用的增强,致使储层深部次生孔隙保存较好;在射孔厚度一定的情况下,以泥质细砂岩为主的特低渗储层并非地层压力越大油气产能便越高,高产油层压力系数为1.2～1.3,这与储层内单砂体有效厚度(砂与泥厚度比)、物性参数、含油饱和度、压力敏感性等因素有关。The reservoir characteristics of upper Es4 member in Chexi depression in Shangdong are disadvantageous to oil gas exploration and development,as lithologies are argillaceous fine-grained sandstones,porosities are 10% to 20% and permeabilities are less than 10×10-3 μm2.In addition,the northern study area is delta front or semi-deep lake facies,where the coefficients of abnormal overpressure are between 1.2 and 1.5.The researches results show that：the main mechanisms of generating abnormal overpressure in Chexi depression is formation uneven compaction,and the secondary is mineral diagenesis.The abnormal overpressure can effectively inhibit the formation temperature increase and diagenesis deepen.In the abnormal overpressure section,the secondary porosity is relatively well preserved for the oil and gas exploration and development.By comparative analysis of single well production capacity of normal pressure zone in southern and overpressure zone in northern,for argillaceous sandstone-based super-low permeability reservoirs,it is not a linear relationship between oil and gas production capacity and formation pressure coefficient,as a higher capacity corresponds to the pressure coefficient between 1.2 and 1.3.The reason for this phenomenon is related to four factors,i.e.single sand body thickness（sand-mud ratio）,physical parameters,oil saturation and pressure sensitivity.

关 键 词：异常高压 成因机制 特低渗储层 储层物性 

分 类 号：TE122.1[石油与天然气工程—油气勘探]