东台坳陷现今地温场特征与油藏分布关系  

Present-day Geothermal Field and Implications for Hydrocarbon Reservoirs in the Dongtai Depression, Eastern China

作　　者：宋宁[1,2] 闫义[3] 张金川[4] 刘振[1] 

机构地区：[1]常州大学石油工程学院,江苏常州213016 [2]中国华电工程(集团)有限公司,北京100035 [3]中国科学院广州地球化学研究所,广东广州510640 [4]中国地质大学(北京)能源学院,北京100083

出　　处：《大地构造与成矿学》2013年第1期164-171,共8页Geotectonica et Metallogenia

基　　金：常州大学人才引进基金资助

摘　　要：东台坳陷为中国东部苏北盆地油气资源最丰富的地区。为了加深对东台坳陷地温场和油藏关系的理解,根据符合地温场研究要求的54口井连续测温资料和243口井试油温度数据,获得了深度1000～3500m地温、E2s-K2t各层位界面地温和各层地温梯度。地温场分布以凹陷或次凹成独立单元,地温随深度加深而线性增高,地温异常不明显。地温梯度总体呈现"浅层低、深层高"的特点,E2s-E2d地温梯度总体在22～30℃/km之间,E1f-K2t在28～38℃/km之间,平均约为30℃/km。不同深度的地温和地温梯度分布模式相似,正向构造单元高,负向构造单元低;而不同层位的地温分布规律则相反,即凹陷内温度高,凸起和隆起上的温度低。基底构造形态、沉积盖层厚度、深大断裂、地下水、地层放射性生热等因素决定了该坳陷总体为温盆特征。大部分地区目前还处在油气液态窗内,绝大多数油藏分布高于60℃的油气勘探开发黄金区域。The Dongtai depression is the richest region of petroleum resources in the Subei Basin of Eastern China. Temperature data from 54 system temperature wells and 243 test wells are used to calculate the subsurface formation temperature at the depths between 1000 and 3500 m and the bottom boundary temperature from the Sanduo Forma- tion （E2s） to Taizhou Formation（K2t）, and the present-day geothermal gradient, respectively. The distribution of geothermal field in the Dongtai Depression is divided into a few independent subunits like sags and sub-sags. In general, the temperature linearly increases with depth and the geothermal gradient in shallow formation is lower than that in the deep formation. The geothermal gradients are 22 - 30℃/km and 28 - 38 ℃/km, respectively, for formations from Sanduo to Dainan （E2s-E2d） and formations from Funing to Taizhou （E1f-K2t） , averaging is about 30℃/km, which indicate the influence of structures of sedimentary rocks on geothermal gradients. The general pattern of temperature at different depth is higher in the positive tectonic units and lower in the negative tectonic units, which is similar to the geothermal gradient. The geothermal field of the Dongtai depression is warm, which is governed by the structures, the thickness of sedimentary, deep faults, groundwater, and radioactive heat production in the strata. Most parts of the Dongtai Depression is still in liquid oil window, the majority of petroleum reservoirs distributes at the underground golden zones of hydrocarbon exploration and development where temperatures are over 60 ℃, and liquid oil migration is at depth of 20 km. The finding of temperature pattern and distribution of oil and gas fields can provide some insights for future exploration.

关 键 词：地温场 地温 地温梯度 油气藏分布 东台坳陷 苏北盆地 

分 类 号：P314[天文地球—固体地球物理学]