塔河油田顺北区块天然气组分特征及成因分析

Characteristics and genesis analysis of natural gas components in Shunbei area of Tahe Oilfield

以塔河油田顺北区块14个天然气样品为研究对象,利用MAT271气体成分质谱仪、DANI GC 1000气相色谱仪、气相色谱-质谱联用仪、Nobleless稀有气体质谱计4种仪器对其组分进行定性和定量分析。结果表明,塔河油田顺北区块天然气中烃类气体含量大于60%,以甲、乙、丙烷为主;非烃含量在10%~40%之间,以N_(2)和CO_(2)为主。研究区样品中含有较多的H_(2)S,其中,二号联原料气、顺北1原料气、顺北7#和顺北1-6H 4个天然气样品中H2S含量较高,其余样品的H2S含量较低,部分样品中还检出了硫醇、硫醚和二硫化碳等。顺北区块天然气主要以腐泥型-油型气为主,且天然气中H_(2)S主要源于硫酸盐热化学还原、烃类热裂解及细菌硫酸盐还原(BSR)混合成因,部分H_(2)S主要由硫醇、硫醚热分解而来。

Taking 14 natural gas samples from the Shunbei area of Tahe Oilfield as the research object,qualitative and semi-quantitative analysis of their components were carried out by using MAT271 mass spectrometer,DANI GC 1000 gas chromatograph,gas chromatography-mass spectrometer and Nobleless rare gas mass spectrometer.The results show that the content of hydrocarbon gas in the natural gas in Shunbei area of Tahe oilfield is more than 60%,mainly composed of CH_(4),C_(2)H_(6) and C_(3)H_(8).The non-hydrocarbon gas content is between 10%and 40%,mainly composed of N_(2) and CO_(2).There are many H2S in the samples in the study area,among which,the content of H2S in the 4 natural gas samples of No.2 united feed gas,Shunbei 1 feed gas,Shunbei 7#and Shunbei 1-6H is higher,while the content of H_(2)S in the other samples is lower.In some samples,thiol,thioether and carbon disulfide are also detected.The natural gas in Shunbei area is mainly sapropel-type natural gas,and the H_(2)S in natural gas mainly comes from the mixed origin of sulfate thermochemical reduction,hydrocarbon pyrolysis and bacterial sulfate reduction(BSR)and part of H2S is mainly from the thermal decomposition of thiol and thioether.