泥质岩中纤维状结构脉体成因机制及其与油气活动关系研究进展  

Progress on Formation Mechanism of the Fibrous Veins in Mudstone and Its Implications to Hydrocarbon Migration

作　　者：王淼 陈勇[1] 徐兴友[2] 张学军[2] 韩云 王成军 曹梦春 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国石化胜利油田地质科学研究院,山东东营257000

出　　处：《地球科学进展》2015年第10期1107-1118,共12页Advances in Earth Science

基　　金：国家自然科学基金项目"东营凹陷盐岩相关流体活动地球化学示踪"(编号:41172111);中央高校基本科研业务费专项资金项目"中国石油大学(华东)青年教师拔尖人才建设工程"(编号:SD2013211151)资助~~

摘　　要：纤维状结构脉体在泥质岩中普遍发育,根据其微观岩相学不同可分为晶体拉伸、延长块状以及特征纤维状结构脉体;根据其生长岩相学差异又可分为拉伸式、向生式和背生式脉体。脉体最终结构主要由裂缝面的形态特征、裂缝宽度和充填裂缝脉体矿物的生长习性所决定。裂缝开启—闭合机理只能用于说明晶体拉伸结构以及延长块状结构脉体的形成过程,背生式特征纤维状结构脉体是在岩石形变过程中裂缝未开启且晶体生长竞争被抑制的情况下通过成脉物质扩散流动运输,晶体由中间面向两侧连续生长形成的。泥质烃源岩中有机质生烃导致异常高压产生的水平裂缝是平行于纹层背生式方解石脉形成的首要条件,在局部范围内可以提高生排烃效率并影响烃类运移的速率和方向,证明油气存在顺平面的侧向运移,因此平行于纹层背生式方解石脉可以作为超高压排烃和油气运移的标志,也可将其作为泥质烃源岩生烃和油气初次运移的主要证据。The fibrous mineral veins are widespread in mudstones. According to the different microscopic mor- phology of the minerals, the fibres can be divided into stretched crystals, elongate-blocky crystals and the very fi- brous crystals. Veins can also be classified according to the growth direction of these crystals into stretched veins, syntaxial veins and antitaxial veins. The resulting texture in the vein depends on the morphology of the fracture sur- face, the width of the fracture and the growth habit of the vein forming mineral. The crack-seal mechanism can only interpret the formation of the Stretched crystal veins and the elongate-blocky crystal veins, and the antitaxial well- developped fibrous veins form without fracturing and the growth competition is inhibited during the rock deforma- tion, which implies that the nutrient transport is by diffusiona] flow transport. Horizontal crack is the primary condi- tion of the formation of the antitaxial bedding-parallel fibrous calcite veins in muddy hydrocarbon source rocks. The formation of the horizontal crack caused by the abnormal high pressure can enhance the hydrocarbon generation effi- ciency and has great effect on the rate and direction of hydrocarbon migration in the local area. The presence of the veins indicates the hydrocarbon fluid can migrate laterally along the layers. The antitaxial bedding-parallel fibrous calcite veins in muddy hydrocarbon source rocks can be the sign of the generation and migration of hydrocarbon un- der the abnormal high pressure condition in petroleum-bearing basins.

关 键 词：泥质岩 纤维状结构脉体 背生式 成因机制 油气活动 

分 类 号：P571[天文地球—矿物学]