摘要
断陷盆地深层致密气作为非常规资源类型之一研究相对较少。以松辽盆地徐家围子断陷沙河子组致密砂砾岩气为例,依据地震、地球化学和储层测试等资料,从构造、沉积、烃源岩、储层、成藏组合角度剖析致密气的成藏条件,结合生烃动力学理论预测致密砂砾岩气的资源潜力。研究认为,大部分斜坡区构造平缓,断穿沙河子组并在晚期持续活动的断层较少,具备成藏构造环境;煤系烃源岩分布广,生气强度大,气源条件十分优越,具备成藏物质基础;扇三角洲、辫状河三角洲相砂砾岩大面积发育,储层整体致密但局部发育次生的高孔、高渗带,具备成藏储集条件;烃源岩与致密储层叠置发育、紧密接触、近源聚集,具备成藏匹配优势。该区钻井揭示整体含气,水平井、直井均获突破,依据生烃动力学方法保守估算致密气资源量为2395×10~8m^3。
Deep tight gas in fault depression basins, as a kind of unconventional resources, is seldom studied. With tight glutenite gas in Shahezi Formation of Xujiaweizi fault depression, the Songliao Basin, as an example, its accumulation conditions were analyzed by using seismic, geochemistry and reservoir testing data from the aspects of structure, sediment, source rock, reservoir and reservoir-forming assemblage. In addition, resource potential of tight glutenite gas was predicted in accordance with hydrocarbon-generation kinetic theories. The results show that majority parts of the slope areas contain gentle structures, and there are few faults penetrating the Shahezi Formation and remaining in continuous activities in later stages, suggesting structural environment for hydrocarbon accumulation. The widely-distributed coal-bed source rocks with high gas-generation intensity provide excellent gas-generating conditions. Glutenites of fan delta and braided-river delta facies develop extensively, and reservoir formations are tight with secondary high-porosity and high-permeability belts in certain parts, providing preservation conditions. Source rocks and tight reservoirs are overlapped in close contact and near source rocks, presenting desirable assemblages. Drilling data indicate that this area contain gas generally. Breakthroughs have been achieved in horizontal and vertical wells. In accordance with hydrocarbon-generation kinetic theories, total resources of tight gas are estimated to be about 2395× 10^8 m3.
出处
《中国石油勘探》
CAS
北大核心
2016年第2期53-60,共8页
China Petroleum Exploration
基金
国家科技重大专项"大型油气田及煤层气开发"(2011ZX05001-001-004)
中国石油天然气股份有限公司重大科技专项"大庆探区非常规油气勘探开发关键技术研究与现场试验"(2012E-2603-02)
关键词
致密砂砾岩气
烃源岩
储层
成藏条件
资源潜力
深层
沙河子组
徐家围子断陷
tight glutenite gas, source rock, reservoir, accumulation condition, resource potential, deep formation, Shahezi Formation,Xujiaweizi fault depression
