准噶尔盆地侏罗系勘探进展及成藏特征

Advancing Exploration of Jurassic in Junggar Basin and Its Sec-ondary Hydrocarbon Pools Formation and Enrichment

准噶尔盆地侏罗系油气勘探经历了三个发展阶段。20世纪50—70年代缓慢发展阶段,勘探在盆地边缘进行,80年代引进数字地震和注蒸汽热采技术,90年代提出“立足大凹陷,寻找大油田”,主攻盆地腹部的部署原则,侏罗系成为盆地主要的勘探目的层。截止到2001年底,侏罗系探明石油地质储量5.28×108t,天然气地质储量253.98×108m3,分别占准噶尔盆地石油和天然气总探明储量的30%和40%.2001年侏罗系原油年产量达502.82×104t,占当年原油总产量的51.9%.侏罗系的优质储量为新疆油田分公司2002年原油产量突破1000×104t,做出了突出的贡献。盆地内发现的3个侏罗系油气田(藏)富集区,它们控制着准噶尔盆地侏罗系原油年产量。侏罗系油气田(藏)成藏和富集的基本特征,反映了准噶尔盆地次生油气藏的基本规律和勘探潜力。油源和断裂是准噶尔盆地侏罗系次生油气藏成藏的必要条件;圈闭、储集层及保存条件是油气田(藏)富集的主要条件。建议下一步要把侏罗系新区和新领域勘探放在首位,加强新区地震勘探和预探,解剖“头屯河—齐古组”地层岩性圈闭,坚持滚动勘探开发,组织八道湾组低渗透油藏和南缘复杂构造攻关。

The hydrocarbon exploration of Jurassic in Junggar basin underwent three stages.In1980s,introduction of digital seismic technique and steam injection or flooding technology for thermal recovery of heavy oil;in1990s,proposing principle of'highlighting large sag to search for giant field'and Taking the basinal hinterland as a major bat-tlefield,hence Jurassic became main target for petroleum exploration;at the end of2001,we obtained OOIP of5.2786×10 8 t,OGIP of253.98×10 8 m 3 ,which account for30%of the total OOIP and40%of the total OGIP found in Junggar basin respectively.In2001,annual crude production from Jurassic was502.8172×10 4 t,accounting for51.9%of total produc-tion the same year.The premium reserves provided from Jurassic contributes greatly to the breakthrough of annual pro-duction of1000×10 4 t in2002by PetroChina Xinjiang Oil.There exist three Jurassic fields(reservoirs)where premium reserves are controlling the annual crude production of Jurassic in Junggar basin.Its6basic characteristics in hydrocar-bon reservoir formation and enrichment could reflect general patterns and potential for exploration of secondary reser-voirs in Junggar basin.It is indicated that oil sources and faulting are prerequisites for formation of secondary hydrocar-bon reservoir,while trap,reservoir and conservation are the major conditions for oil and gas field(reservoir)enrichment.Therefore,in next stage,new areas of Jurassic and new domain prospect should be put in the first place,along with plac-ing emphasis on seismic prospect and pre-prospect of Jurassic,anatomizing litho-stratigraphic trap in Toutunhe-Qigu formation,continuing rolling exploration and development,and carrying out tackling key problem to low permeability reservoir of Badaowan formation as well as complex structures in southern margin of Junggar basin.