准噶尔盆地玛湖——盆1井西复合含油气系统地层高压分布与成因

Distribution and origin of the super pressure in the Mahu-Penyijingxi multi-source petroleum systems,Junggar Basin

玛湖———盆1井西复合含油气系统是准噶尔盆地油气分布最集中的地质单元.研究表明该地区地层压力类型丰富,侏罗系底部及以下地层在凹陷内一定深度以下普遍发育高压,在莫索湾凸起的中南部侏罗系则整体处于超压状态.沉积型欠压实作用使得凹陷内侏罗系底部及以下储层流体以高压分布为主,腹部4 400 m以下地层中的高压形成则与成岩型欠压实作用有关,而构造挤压及叠置作用对西北缘高压的形成起主要作用.

Mahu-Penyijingxi multi-source petroleum systems are the most important geological unit of oil and gas distribution in the Junggar Basin. Researches show there are many types of strata pressure, super pressure in certain depth below the bottom of the Jurassic stratum, and also overpressure in the whole Jurassic stratum in central and southern of Mosuowan salient. Under-compaction induced by sedimentation is the main reason for the super pressure below the Jurassic, and is caused by diagenesis which might arouse the super pressure under 4 400 m in the abdomen of the Junggar Basin, and the compression and imbricate structure are important for the overpressure occurred in the NW margin.