摘要
为系统研究鄂尔多斯盆地东缘地应力分布特征及其对煤层气勘探开发的影响,结合区域构造特征和煤层气注入压降试井参数,获取了地应力场的演化及其在平面和垂向上的变化规律,分析了其对煤层气储层的控制作用。结果表明:研究区主应力由燕山期的NW—SE向转变为喜山期的NE—SW向,对地层挤压有一定的释放作用;侧压系数一般小于1,总体处于拉张环境;现今储层压力普遍偏低,大多处于欠压状态;地应力与埋深总体上呈正相关关系,大致以800~1 100 m为过渡带,在更深的地层中相对挤压。研究区总体有利于煤层气勘探开发,但不同地区的开发转折深度存在差异,柳林地区为800 m,韩城为1 000 m。
For a better analysis of the in-situ stress distribution and its influence on coalbed methane exploration and development in east margin of Ordos Basin,the evolution of in-situ stress field and its variation of horizental and vertical extensions were acquired,and its effect on coalbed methane reservoirs was discussed,based on regional tectonic evolution and injection falloff well test parameters.The results show that:the direction of principal stress changed from NW-SE in Yanshan Movement to the NE-SW in Xishan Movement,which released the strata compaction to some extent;the lateral pressure coefficient is generally lower than 1,which shows that the study area is of an tension environment;the present reservoir pressures are low,result in the most of the reservoirs in under-pressure conditions;the in-situ stresses generally show a positive linear relationship with depth,which are generally banded by the 800 ~1,100 m,with the deeper strata in more compressed conditions.The study area is generally favorable for coalbed methane development,however,different areas show different development transition depths,with the Liulin area of 800 m and Hancheng of 1,000 m.
出处
《矿业科学学报》
2017年第5期416-424,共9页
Journal of Mining Science and Technology
基金
国家自然科学基金青年基金(41702171)
关键词
煤层气
地应力
储层压力
鄂尔多斯盆地东缘
coalbed methane
in-situ stress
reservoir pressure
east margin of Ordos Basin
