准噶尔盆地中部4区块储层主控因素

准噶尔盆地中部4区块储层以长石岩屑砂岩和岩屑砂岩为主，成分成熟度低，塑性岩屑含量高，成岩作用已进入晚成岩A期。孔隙类型以剩余原生粒间孔为主，另有少量的次生溶蚀孔隙和微孔隙。成岩压实作用是控制储层的主要因素，相对优质储层一般发育在辫状河三角洲平原、前缘或三角洲前缘水下分支河道，早期产生的异常高压抑制了成岩作用，保存了储层的孔隙。头屯河组及其以上地层、董2井北东埋藏较浅地区和早期形成的异常高压带为勘探的有利目标。

Main factors controlling reservoirs of the 4th block in the middle of Junggar Basin

In the 4th block of the middle of Junggar Basin, the reservoir li-thology consists of feldspathic lith - arenite and lithic sandstones with lower compositional maturity, higher content of plastic lithic, and the diagenesis is in the A substage of late diagenesis period. The pore types are mainly the remaining primary intergranu-lar pores,with a few secondary dissolution pores and micropores. Diagenetic compaction is the main factor of controlling reservoirs. The relatively good reservoirs develop on the subaqueous branch channels of deltaic plain and front or deltaic front of braided channels, whose pores can be preserved since the early -formed abnormal pressure restrained the diagenesis. The exploration targets include the Toutunhe Formation and the above strata, the shallow - burial area toward northeast of Dong 2 well,and the early - formed abnormal pressure belts.