松辽盆地南部让字井斜坡带超压特征及其对源下油藏运聚模式的控制  

Characteristic of Overpressure and Its Control on Migration and Accumulation Model for Hydrocarbon Reservoirs below Source Rocks in Rangzijing Slope Zone of Southern Songliao Basin

作　　者：李丹 董春梅 林承焰 任丽华 谭丽娟 谢晶晶 

机构地区：[1]中国石油大学地球科学与技术学院,山东青岛266580 [2]中国石油大学山东省油藏地质重点实验室,山东青岛266580

出　　处：《天然气地球科学》2014年第3期326-332,共7页Natural Gas Geoscience

基　　金：国家科技重大专项(编号:2011ZX05009-003);中央高校基本科研业务费专项资金项目(编号:11CX06005A);吉林油田科研项目联合资助

摘　　要：对松辽盆地南部中央坳陷区让字井斜坡带青山口组超压分布特征进行分析，在此基础上开展超压对源下油藏运聚模式的控制研究。结果表明，超压段具有低地震速度、低密度、低电阻率和高声波时差的“三低-高”响应特征。纵向上单井压力结构呈“三层式”，不同二级构造带超压分布的深度范围不同，长岭凹陷为1700～2300m，扶新隆起为1100～1700m，华字井阶地为1300～1800m，其分布具“层控”特征。应用等效深度法计算超压值多在10～14MPa之间，平面分布与构造埋深呈正相关关系。油源、超压与T2断层的耦合使超压运移成为可能，超压作用下油气理论向下排运距离为272～510m，大于扶余油层厚度；超压与源下输导体的匹配导致4种运移模式的纵向演变。源下油藏油气显示厚度与青一段剩余压力呈正相关。研究区油气实际下排距离多在100m以内，远小于理论值，原因在于“优势泄压仓”的发育，其发育位置不同造成油气向下排运距离的差异。总体上源下扶余油层Ⅱ砂组、Ⅲ砂组为超压作用下油气优势充注层段。The distribution of overpressure is analyzed for Qingshankou Formation from Rangzijing Slope Zone in southern Songliao Basin. The hydrocarbon migration and accumulation models of reservoirs below the source rocks controlled by the overpressure are studied. The results show ＂three low and one high＂ that the overpressure zone is characterized by low seismic velocity,low density,low resistivity and high acoustic travel time. The well pressure is a ＂three-layered＂ structure vertically. The depth of overpressure slrata va ries in different secondary structural zone, which suggests the feature of ＂strata-controlied＂. The main range of overpressure is 10 to 14MPa,which is calculated by the equivalent depth method. There exists it positive correlation between the distribution of overpressure and the depth. The coupling of oil source, overpressure and T2 faults make it possible to migrate downward 272 to 510m theoretically,deeper than the Fuyu oil thickness. The match of overpressure and conduit system under the source rocks leads to vertical evolution of 4 migration patterns. There is a positive correlation between the thickness of hydrocarbon shows in the reservoir and the overpressure of the source rocks. The existence of ＂dominant pressure leakage compartment＂ results in shorter down-migration distance which is mainly within 100m in fact,and the down-migration distance varies with the change of ＂dominant pressure leakage compartment＂ location. O verall, the II and III sand groups are the preferable layer which is filled with hydrocarbon in Fuyu oil layer.

关 键 词：超压分布 运聚模式 源下油藏 优势泄压仓 青山口组 让字井斜坡带 

分 类 号：TE122.1[石油与天然气工程—油气勘探]