摘要
柴西地区天然气具备较大的勘探潜力,然而主要生气中心、主力气源岩、天然气成藏关键时刻尚未明确,制约了天然气勘探进程。选取在含油气系统模拟中应用最广的PetroMod软件,输入相关参数,恢复剥蚀量,建立柴西地区古近系—新近系三维地质模型,运行后得到各套烃源岩成熟度平面图、生气强度图、运聚方向图以及生气量,由此可以确定主力气源岩为下干柴沟组上段(E^2_3)和上干柴沟组(N_1);指出天然气平面分布受源岩成熟度的控制,天然气位于成熟—高成熟源岩区及附近;主要生气凹陷为红狮、小梁山和茫崖东3个凹陷,围绕生气凹陷周缘的构造高部位是天然气的运聚方向;主要生气期为第四纪(Q_(1+2))和上新世晚期(N^3_2),关键时刻为N^2_2末。在以上研究的基础上,指出狮子沟—油砂山—英东—大乌斯、油泉子—开特米里克—油墩子和小梁山—南翼山—大风山构造带是下步柴西地区天然气勘探的重点领域。
There is great exploration potential of natural gas in the western Qaidam Basin, however the gas generation depressions, major source rocks and critical moment of gas accumulation are not clear, and the present situations restrict the gas exploration process.The Paleogene and Neogene three-dimensional geo- logical model for western Qaidam Basin was established by using the software PetroMod, which is most widely used in the petroleum system simulation. After entering the relevant parameters and running the program,the following maps were obtained,such as maturity distribution the gas generation intensity of each source rock, gas migration directions and gas-generation quantity. According to the above maps, it is determined that the major source rocks are the upper member of the Lower Ganchaigou Formation （E3^2） and the Upper Ganchaigou Formation （N1）.It is also pointed out that the distribution of natural gas is con- trolled by the source rock maturity and the natural gas is located in the mature and high mature source rock area, and main gas-generation depressions are Hongshi, Xiaoliangshan and eastern Mangya Depres- sions.Structural high parts around the depressions are the gas migration directions ,and the main gas gener- ation periods are Quaternary （Ql＋2） and Late Pliocene （N~） and the critical moment is at the end of N~. On the basis of the above research, favorable zones for natural gas distribution can be predicted that the Shizigou-Youshashan-Yingdong-Dawusi, Youquanzi-Kaitemilike-Youdunzi, and Xiaoliangshan-Nanyishan- Dafengshan structural belts are favorable zones for natural gas accumulation.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2017年第1期82-92,共11页
Natural Gas Geoscience
基金
国家大型油气田及煤层气开发科技重大专项(编号:2016ZX05007)
中国石油重大科技专项"柴达木盆地建设高原大油气田勘探开发关键技术研究与应用"(编号:2016E-0102)联合资助
关键词
柴西
含气系统
主力气源岩
关键时刻
有利区带
Western Qaidam Basin
Gas system
Major gas source rocks
Critical moment
Favorable zones
