金刚烷化合物在克拉美丽地区高熟油气成熟度判识中的应用

Application of diamondoid to evaluate maturity of high-maturity oil in Kelameili Area

针对常规生物标志物参数在成熟演化阶段时就已达到了平衡值,难以有效判识高熟原油成熟度的问题,本次工作利用色谱-质谱-质谱方法分析了克拉美丽地区原油中金刚烷化合物的含量,探讨了金刚烷参数指标在克拉美丽地区高熟油气成熟度判识的适用性。研究结果显示,金刚烷异构化指标能够较有效判别克拉美丽地区高、过成熟原油的成熟度,该区石炭系来源的原油成熟度Ro,Easy在1.8%~2.6%之间,五彩湾的原油成熟度低于克拉美丽气田的原油。滴南凸起滴水泉西断裂北侧的原油成熟度自东向西沿着DX21→DX10→DX18→DX27→DX14→DX17→DX171先增大后减小,在DX18井区成熟度最高,认为滴水泉凹陷和东道海子-五彩湾凹陷两大石炭系烃源灶热演化程度存在差异,并存在沟通两大有效烃源灶的断裂带,不同热演化程度生成的油气在沿断裂带向滴南凸起运聚过程中发生混源,造成原油成熟度呈现规律变化的现象。

Once biomarker parameters reach an equilibrium value at the mature stage,it becomes difficult to evaluate the maturity degree of oil.In this paper,the diamondoid content of crude oil from the Kelameili area was analyzed by GC/MS/MS method,and the applicability of the diamondoid indices to evaluate the maturity of high-maturity oil in the Kelameili area was discussed.The results show that diamondoid indices are effective parameters to evaluate the maturity of high and over-mature crude oil in the Kelameili area.The maturity of crude oil originating in Carboniferous sources in the area is between 1.8%and 2.6%,and the maturity of crude oil in the Wucaiwan oilfield is lower than that of crude oil in the Kelameili oilfield.Furthermore,the maturity of crude oil on the north side of the west fault in the Dinan uplift first increases,and then decreases from east to west along DX21→DX10→DX18→DX27→DX14→DX17→DX171,the maturity being highest in the DX18 well area.It is concluded that the thermal evolution degree of Carboniferous source stoves in the Dishuiquan depression and the Dongdaohaizi-Wucaiwan depression are different,and there is a fault zone that connects these two effective hydrocarbon source stoves,different thermal evolution levels of oils mixed in the process of fusion along the fault zone,and resulting in a regular maturity change of crude oil.