摘要
柴达木盆地致密油资源丰富,总资源量可达8.57×10^8t。近年来,英西地区湖相致密碳酸盐岩勘探取得突破,发现了规模储量。整体上,英西地区为一晚期隆起的大型背斜构造,纵向上具有"双层结构"特征,其浅层为受滑脱断层控制而形成断层传播褶皱,深层为复杂的冲断构造。英西地区下干柴沟组上段(E23)沉积期为咸化湖相环境,以盐岩层底为界,纵向上划分为盐间和盐下。盐下主要沉积泥质岩、碳酸盐岩和少量硫酸盐,同时也是优质烃源岩发育层段;盐间主要沉积了碳酸盐岩、盐岩和碎屑岩。该区烃源岩主要为一套深灰色灰质泥岩,其生烃母质以藻类为主,对烃产率贡献高达60%。储层总体为各种类型的灰云岩,普遍发育晶间孔,局部发育角砾化孔(洞)和溶蚀孔,平均孔隙度为6.2%,平均渗透率为0.61μm^2。按照源-储配置关系可将油藏划分为两种类型,即盐下"自生自储"型和盐间"下生上储"型。研究和勘探实践证实,TOC、碳酸盐岩含量、储层孔隙度和脆性是"甜点"评价的重要指标,通过各主要参数的叠加分析对研究区甜点分布进行了分级评价。三维地震处理与解释、水平井多段多簇压裂等关键技术的应用实现了对英西地区致密碳酸盐岩油藏的有效动用。
Qaidam Basin is rich in tight oil resources,with a total resource of 8.57 ×108 t.In recent years,some new achievements were gained in lacustrine tight carbonate rock exploration in Yingxi area,and a massive tight oil reserve were found.In general,the structure in Yingxi area is a large-scale anticline,its structural style was characterized by "double-layer structure"in vertical.In the shallow layer,a series of fault-propagation folds were formed by detachment faults,the deeper part was characterized by the development of complex thrust structure.The sedimentary environment during the period of deposition of the upper member of Lower Ganchaigou Formation(E23)was a saline lake,the stratum was subdivided into"intra-salt"layer tracts and"below-salt"layer tracts by using the basal of salt layers as a boundary.The predominant rock types of the"below-salt"layer tracts were argillaceous rock,carbonate rock and some sulfate rock,meanwhile the good hydrocarbon source rocks were mainly developed in this interval as well.Whereas,the main rock types developed in the‘intra-salt’layer tracts were carbonate rock,clastic rock and halite.The main type of the source rock in the study area was dark-gray lime-mud stones,the main maceral of kerogen was Botryococcus,which had a contribution of 60%to hydrocarbon generation.The predominant rock type of reservoir was the lime-dolostone,intercrystalline pores developed widespreadly,and inter-breccia pores/caverns and dissolution pores were developed locally either.The average porosity and permeability of reservoirs was 6.2% and 0.61μm2,respectively.Based on the source-reservoir relations,the types of oil pool was subdivided into"self-generation and self-storage"type and "new source to old reservoir"type,both kinds of oil pool types were accumulated in"below-salt"layer tracts and"intra-salt"layer tracts separately.Study and exploration practices indicated that the TOC,carbonate content,porosity and brittleness of reservoirs were important ideces in sweet areas evaluation.Sweet areas w
作者
张道伟
马达德
伍坤宇
吴颜雄
夏晓敏
张审琴
张晓秋
Zhang Dao-wei;Ma Da-de;Wu Kun-yu;Wu Yan-xiong;Xia Xiao-min;Zhang Shen-qin;Zhang Xiao-qiu(Research Institute of Exploration & Development of Qinghai Oilfield Company,CNPC,Dunhuang736202,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2019年第8期1134-1149,共16页
Natural Gas Geoscience
基金
国家科技重大专项“重点盆地致密油资源潜力、甜点区预测与关键技术应用”（编号：2016ZX05046-006）
国家科技重大专项（编号：2016ZX05046）
中国石油天然气集团公司重大科技专项（编号：2016E-01）联合资助
关键词
英西地区
咸化湖盆
致密油
葡萄藻
配套技术
甜点预测
Yingxi Oilfield
Saline lake basin
Dense oil
Botryococcus
Supporting technology
Sweet area evaluation
