大民屯凹陷前进潜山带沈288区块太古宇潜山油藏特征

Characteristics of Archean Buried Hill Reservoir in Block Shen-288 of the Qianjin Belt in Damintun Depression

揭示前进潜山带沈288区块太古宇潜山油藏特征对大民屯凹陷潜山油藏勘探具有重要意义。在对大民屯凹陷前进潜山带沈288区块太古宇潜山油藏岩性分析、地层划分的基础上对比了不同层段裂缝发育特征及控制因素。研究结果表明,大民屯凹陷前进潜山带沈288区块太古宇潜山油藏岩性主要包括区域变质岩、混合岩以及角闪岩和煌斑岩类,通过锆石原位年龄确定该潜山地层属于太古宇鞍山群,可以划分成3套潜山地层:第1套岩性以变粒岩、黑云斜长片麻岩为主;第2套岩性以黑云角闪斜长片麻岩为主;第3套岩性以混合花岗岩为主,其中以第3套地层裂缝最为发育,是控制油气成藏的最主要原因。3套地层所处的构造应力背景相同,裂缝发育程度不同主要是因为岩性的差异。

Progress revealing the feature of Archean buried hill reservoir in block Shen-288 of Qianjin belt is of great significance to the exploration of buried hill reservoir in Damintun Depression. The analysis of the characteristics and controlling factors of different layers of fracture development on the basis of lithology a- nalysis and stratigraphic division to Archean buried hill reservoir in block Shen-288 of the Qianjin belt in Damintun Depression, shows that the lithology of this area mainly includes the regional metamorphic rock, migmatite and amphibolite and lamprophyre. By in situ zircon age determination, this buried hill formation belongs to the Archean Anshan Group and can be divided into three strata： the first set is mostly granulite and migmatitic gneiss, the second set mainly biotite, hornblende and plagioclase gneiss, and the third set mainly in the mixed granite. The fractures of the third set are developed, which is the main reason control- ling oil and gas pool. Construction stresses of the three sets of strata are at the same background, while dominated by the difference of lithology, the degree of fracture development is different.