摘要
对大牛地气田下古气藏硫化氢形成机理进行实验研究。高温高压热化学反应结果显示,在有地层水和石膏(硫酸钙)存在的模拟地层环境中,检测到硫化氢的产生,与原生气形成机理中TSR成因相符合,说明地层水以及石膏(硫酸钙)的存在是高温高压环境产生硫化氢的必备条件;硫同位素及分馏值测定结果显示,全岩及气样的δ34S同位素平均值分别为27.462‰和17.858‰,硫同位素分馏值平均值为9.604‰,分馏值范围在TSR成因范围内。利用气井岩样开展硫化氢次生气形成机理模拟实验,检测产生了硫化氢。综合分析,认为大牛地气田下古气藏硫化氢是TSR产生原生硫化氢以及黄铁矿生成次生硫化氢的共同结果。
The lower Paleozoic gas reservoir of Daniudi gas field contains different degrees of hydrogen sulfide,which belongs to the range of low and micro sulfur.So there are certain risks in the safe production of gas reservoir.The results of thermochemical reaction under high temperature and pressure show that the generation of hydrogen sulfide is detected in the simulated formation environment with formation water and gypsum(calcium sulfate),which is consistent with TSR genesis in the formation mechanism of primary gas.It shows that the existence of formation water and gypsum(calcium sulfate)is the necessary condition for the generation of hydrogen sulfide in high temperature and high pressure environment,and the absence of one of them can not generate hydrogen sulfide.The results of sulfur isotope and fractionation show that the average value ofδS is 27.462‰and 17.858‰respectively,the average value of sulfur isotope fractionation is 9.604‰,and the fractionation range is within the genetic range of TSR.The formation mechanism of hydrogen sulfide secondary gas is simulated by using gas well rock samples.It is found that the test paper turned black,indicating that FeS2,the main component of pyrite in gas reservoir,can react with fracturing fluid to produce hydrogen sulfide.Based on the overall analysis,the hydrogen sulfide in the lower Paleozoic gas reservoir of Daniudi gas field is considered to be the common result of generation of primary hydrogen sulfide by TSR and secondary hydrogen sulfide by pyrite.
作者
王萍
WANG Ping(Research Institute of Petroleum Engineering, Sinopec North China Oil & Gas Branch,Zhengzhou 450006, Henai, China)
出处
《承德石油高等专科学校学报》
CAS
2020年第6期1-4,共4页
Journal of Chengde Petroleum College
基金
“十三五”国家科技重大专项(低丰度致密低渗油气藏开发关键技术):2016ZX05048。
关键词
大牛地气田
形成机理
硫同位素
热化学硫酸盐还原反应
硫化氢
Daniudi gas field
generation mechanism
sulfur isotope
thermochemical sulfate reduction(TSR)
hydrogen sulfide(H2S)
