摘要
四川盆地志留系小河坝组砂岩认识程度较低、勘探方向不明确。应用野外露头、探井、地震和测井等资料,系统研究四川盆地小河坝组砂岩的沉积、储层、成藏等油气地质特征,评价勘探潜力和方向,得到以下4点认识:①四川盆地小河坝组砂岩以粉砂岩为主,发育2类砂体,分别为前陆盆地三角洲前缘远端砂坝砂体和夹于前三角洲泥岩中的薄层砂体,2类砂体在川东地区大面积分布;②小河坝组砂岩储层整体低孔隙度低渗透率、特致密,后期成岩作用致使储层致密化,局部发育相对较高孔层段,成藏期可能发育较好储层;③小河坝组砂岩储层、龙马溪组优质泥质烃源岩和韩家店组厚层泥页岩盖层,形成一套优质的生储盖成藏组合,川东地区的开江古隆起形成与演化有利于小河坝组砂岩的成藏和保存;④小河坝组砂岩是四川盆地天然气勘探的潜在领域,2类砂体都有一定潜力,其中远端砂坝砂体有利勘探面积约为1×10^4km^2。成果对提高该领域地质认识、指导天然气勘探,有重要意义。
The sandstone of the Silurian Xiaoheba Formation in Sichuan Basin is poorly recognized and the exploration direction is not clear. Based on field outcrops,exploration wells,seismic and logging data,the basic hydrocarbon geology characteristics of strata,sediments and reservoirs of Xiaoheba Formation in Sichuan Basin and its adjacent areas are systematically studied. By analyzing the reservoir-forming assemblage and evolution and evaluating the exploration potential and direction,the following four points are obtained. Firstly,siltstone and mudstone are mainly developed in Silurian Xiaoheba Formation in Sichuan Basin and its adjacent areas and the whole formation is a delta sedimentary system of foreland basin. The siltstone development zone is the distal bar of delta front and the mudstone development zone is prodelta. Secondly,the siltstone in Xiaoheba Formation is a tight reservoir with low porosity and permeability,and the relatively high porosity reservoir is locally developed. Thirdly,an excellent source-reservoir-cap assemblage has been formed by taking thick shale of Longmaxi Formation as source rocks,siltstone of Xiaoheba Formation as reservoirs and thick shale of Lower Hanjiadian Formation as caprocks. The formation and evolution of Kaijiang paleo-uplift are beneficial to the accumulation and preservation of siltstone in Xiaoheba Formation. Finally,the siltstone in Xiaoheba Formation is a potential exploration zone for natural gas in Sichuan Basin,and the distal sand bar is the most potential one with an area of about 10 000 km^2. The results are of great significance for improving geological knowledge and guiding natural gas exploration in the field.
作者
杨威
魏国齐
李德江
刘满仓
谢武仁
金惠
沈珏红
郝翠果
王小丹
YANG Wei;WEI Guo-qi;LI De-jiang;LIU Man-cang;XIE Wu-ren;JIN Hui;SHEN Jue-hong;HAO Cui-guo;WANG Xiao-dan(PetroChina Research Institute of Petroleum Exploration and Development,Langfang 065007,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2020年第1期1-12,共12页
Natural Gas Geoscience
基金
国家科技重大专项“大型油气田及煤层气开发”（编号：2016ZX05007-002）资助~~
关键词
四川盆地
志留系
小河坝组
砂岩
成藏组合
勘探方向
油气
Sichuan Basin
Silurian
Xiaoheba Formation
Sandstone
Reservoir-forming assemblage
Exploration direction
Hydrocarbon
