川西海相天然气勘探难点及对策

“十五”期间,川东北海相特大型气田的发现引发了新一轮南方海相地层油气勘探热潮,中石化在川西坳陷中段部署了针对海相层位的亚洲最深科学探井--川科1井。但四川盆地构造演化复杂、多源多期多系统成藏、油气高演化等特定地质条件,使得一系列基础地质和成藏难题尚待解决,主要有：高演化烃源岩和资源评价、复杂构造运动背景下的成藏机理、油气保存条件评价等问题。为此,对川西海相天然气勘探的难点进行了分析,并指出了包括：烃源-资源、储层、保存条件、聚集条件、川西海相油气成藏地质理论、川西海相油气地质分析评价方法技术系列等在内的6个科技攻关方向,总结出“强化盆地构造演化与恢复研究,重视油气成藏地质研究,加大基础地质研究投资力度,设立一批围绕海相油气成藏地质理论和地质分析评价方法技术系列的专项课题,不要大而全,强调专项攻关,各个击破”的技术对策,同时提出了开展13个专项研究的建议。

CHALLENGES AND SOLUTIONS OF MARINE GAS EXPLORATION IN WEST SICHUAN BASIN

The discovery of a giant marine gas field in the northeastern Sichuan Basin during the tenth "Five year Plan" period triggered a new surge of exploration of marine oil and gas reservoirs in South China. The well Chuanke 1, the deepest scientific exploratory well in Asia, was drilled by the company of Sinopec in the western Sichuan depression to study the marine strata. However, the geologic conditions in the Sichuan Basin are complicated by the complex structural evolution, hydrocarbon reservoiring characterized by multiple sources, multiple phases, multiple systems, and highly mature oil and gas, thus many challenges still exist in respects of study of the basic geology and hydrocarbon reservoiring, including assessment of highly mature source rocks and resource volumes, mechanism of hydrocarbon reservoiring in a background of complex tectonic movement and evaluation of preservation conditions of oil and gas. This paper analyzes the difficulties faced by marine gas exploration in the western Sichuan Basin, and presents 6 directions for research, such as source rocks(resource volumes), reservoirs, preservation conditions, accumulation conditions, geologic theory of marine oil/gas reservoiring and methodologies for analysis and evaluation of petroleum geology in the western Sichuan Basin. Based on the above analysis, some technical measures are proposed, including "strengthening study of structural evolution and reconstruction in the Sichuan Basin, paying attention to organic geochemical study of oil/gas reservoiring, increasing investment in basic geologic research, carrying out study of geologic theory of marine oil/gas reservoiring and geologic analysis and evaluation, not requiring the research projects being large and complete, highlighting special research and tackling technical problems one by one". In addition, 13 special research projects are proposed.