Present-Day Geothermal Field and Implications for Hydrocarbon Reservoirs in the Dongtai Depression, Eastern China
详细信息
- 责任者：Song Ning (School of Petroleum Engineering ; Changzhou University ; Changzhou 213016 ; China) ; Yan Yi
- 刊名：Geotectonica et Metallogenia
- 出版年：2013
- 卷期：37(1)
- 关键词：地热场 ; geothermal fields ; 油气藏形成 ; reservoir formation ; 苏北盆地 ; Subei Basin
- 页码：p.164-171
- 图表：illus., 27 refs.
- 分类号：1003
- issnNo：ISSN1001-1552
- isbnNo：CN44-1595/P
摘要
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 Formation (Es2) 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.