摘要
川西南五指山—美姑地区勘探程度较低,工区内无钻井,在大量野外地质调查、样品系统采集及分析化验的基础上,对可能烃源岩的分布、厚度、有机质丰度、类型、成熟度等特征进行了综合分析,发现研究区主要发育筇竹寺组、龙马溪组、临湘-五峰组和须家河组泥页岩类烃源岩和栖霞组、茅口组碳酸盐岩类烃源岩。采用有机碳法对资源量进行了计算,6套烃源岩的总生烃量达1 193.89×10^11m^3,总资源量为5.157×10^11m^3,表明具有良好的油气勘探潜力。其中,龙马溪组烃源岩厚度大、分布广,尤其是中、下部有机质丰度高,有机碳质量分数为0.40%-6.07%,资源量为2.12×10^11m^3,占总资源量的41.28%,为最好的烃源岩;其次为筇竹寺组烃源岩,资源量为1.218×10^11m^3;栖霞组和茅口组烃源岩的有机质丰度较高,大部分地区有机碳质量分数大于0.4%,资源量分别为0.99×10^11,0.42×10^11m^3;临湘—五峰组和须家河组烃源岩在工区内厚度较薄、分布局限,生烃量较为有限。综合分析表明,雷波鼻凸北部、马边—绥江凹陷和凉东—美姑断凹中部资源量丰富、保存条件有利,是下一步最有利的勘探目标区。
A low degree of exploration is the actuality of Wuzhishan-Meigu area in Southwest Sichuan Province as none exploratory well is drilled. The distribution, thickness, abundance, types and maturity of potential source rocks are studied based on the field geological investigation and chemical analysis. The results show that the regional main source rocks are Qiongzhusi Formation of Lower Cambrian, Linxiang-Wufeng Formation of Upper Ordovician, Longmaxi Formation of Lower Silurian, Maokou Formation-Qixia Formation of Lower Permian and Xujiahe Formation of Upper Triassic, including carbonate source rocks and mud source rocks. Total organic carbon method is used with the simulation technique to calculate the hydrocarbon genetic content. The total volume of hydrocarbons generation amounts to 1 193.89 ×10^11 cubic meters and total resources, 5. 157×10^11 cubic meters, which indicates the area has a great exploration potential. It is believed that the Longmaxi Formation is the best major effective source rocks, with wide distribution, big thickness and high abundance of organic matter, with the resources up to 2.12×10^11 cubic meters, about 41.28% of the total resources. Especially, the organic matter abundance is higher and reaches from 0.32% to 6.07% in middle and lower parts of the Formation. Qiongzhusi Formation of Lower Cambrian is the second effective, with the total resource up to 1. 218 ×10^11 m^3. The source rocks in Oixia Formation and Maokou Formation contain abundant organic matter, with TOC value more than 0.2 % in most part of the study area, accounting for 0.99 ×10^11m^3 ,0.42 ×10^11m^3 respectively. While LinxiangWufeng Formation and Xujiahe Formation are thin, with restricted distribution of the source rocks and limited generation potential of hydrocarbons. An integrated study shows that the northern part of Leibo nose salient, Mabian-Suijiang Sag and the middle part of Liangdong-Meidu Fault Depression are prospective exploration regions, because of their abundant hydrocarbon resources and good conditions of hydrocarbon preservation.
出处
《地质科技情报》
CAS
CSCD
北大核心
2009年第4期41-46,共6页
Geological Science and Technology Information
基金
国家"十五"重点科技攻关项目(2004BA616A-05)
关键词
有效烃源岩
资源评价
生烃强度
资源潜力
五指山—美姑地区
effective source rock
resources evaluation
hydrocarbon-generating intensity
resources potential
Wuzhishan- Meigu area
