摘要
洼槽区已成为二连盆地富油凹陷增储上产的重要领域,深入认识其成藏条件与成藏模式,是提高勘探成效的关键。通过对乌里雅斯太凹陷南洼槽生烃能力、油气相态、沉积砂体分布、储层特征以及成藏期等分析,探讨了富油凹陷洼槽区油气成藏的主要有利条件及成藏模式。乌里雅斯太凹陷南洼槽洼槽区优质烃源岩较斜坡带更为发育,有效生烃强度大,热演化程度较高,处在油气混相生成阶段。洼槽区砂体来源于西部陡坡带,砂体规模较大,延伸较远,储集空间主要为粒间溶孔、粒内溶孔等次生孔隙,在埋深2300~2500 m、2800~3000 m区间存在异常孔隙发育带,具备成为优质储层的条件。凹陷存在2期主要生烃及成藏过程:第一期主要在斜坡带发育,烃源岩早期生成的油气聚集成藏;第二期主要在洼槽区发育,成藏动力强,烃源岩中后期生成的油气准连续聚集成藏,形成近源致密油和源内页岩油气成藏模式。乌里雅斯太凹陷南洼槽洼槽区勘探与研究成果对其他富油凹陷洼槽区勘探具有现实的指导意义。
At present,the trough area has become an essential target for increasing the reserves and enhancing the production capacity in the oil-rich sags of Erlian Basin.In-depth understanding of its oil/gas accumulation conditions and accumulation patterns is the key to improve the successfulness of exploration.The southern trough of Wuliyasitai Sag in Erlian Basin is chosen as the research object.Based on the analysis of the hydrocarbon generation capacity,the phase of the generated oil/gas,the distribution of sedimentary sand bodies,the characteristics of the reservoir,and the timing of oil/gas accumulation,the main favorable conditions and patterns of oil/gas accumulation in the trough area were discussed.The results indicate that the high-quality source rock in the southern trough of Wuliyasitai Sag are much better than that in the slope belt,presented by higher generation intensity of the effective hydrocarbon,higher thermal evolution degree,and being in the stage of oil and gas generation.The sand body which occurred in large scale in the trough area was derived from the western steep slope belt and extended far.The reservoir space is mainly composed of secondary pores such as intergranular dissolved pores and intragranular dissolved pores.An abnormal pore occurred in the intervals of 2300-2500 m and 2800-3000 m in burial depth,providing good conditions for a high-quality reservoir.Two main stages of hydrocarbon generation and accumulation occurred in the sag.The first stage is the oil and gas generated in the early time and mainly accumulated within the reservoir in the slope belt.The second stage mainly occurred in the trough area where is characterized by greater charging dynamics during oil/gas accumulation.The quasi-continuous accumulation of oil and gas which were generated in the middle and late stages in the source rock,results in forming a pattern of near-source stratigraphic lithologic oil reservoirs-tight oil and a pattern of the intrasource shale oil/gas.This would be a guidance for the exploration in t
作者
江涛
张锐锋
项鑫
谢佩宇
张宇飞
韩琪
李彬
钟雪梅
徐婕
JIANG Tao;ZHANG Ruifeng;XIANG Xin;XIE Peiyu;ZHANG Yufei;HAN Qi;LI Bin;ZHONG Xuemei;XU Jie(PetroChina Huabei Oilfield Company,Renqiu 062552,China;No.2 Mud⁃logging Company,BHDC,CNPC,Renqiu 062552,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2022年第9期1409-1420,共12页
Natural Gas Geoscience
基金
国家科技重大专项“华北探区致密油资源潜力、甜点区预测与关键技术应用”(编号:2016ZX05046-006-007)资助
关键词
洼槽区
有利条件
成藏模式
乌里雅斯太凹陷
二连盆地
Trough area
Favorable conditions
Accumulation pattern
Wuliyasitai Sag
Erlian Basin
