带气顶特稠油油藏流体性质的不确定性探讨——以L16油田为例  

Uncertainty Fluid Property Explore to Very Heavy Oil Reservoir with Gas Cap——Taking L16 Oilfield as an Example

作　　者：李卓林 田冀 谭先红 刘新光 

机构地区：[1]中海油研究总院,北京100027

出　　处：《油气井测试》2016年第4期6-9,16,共5页Well Testing

基　　金：中海石油(中国)有限公司重大专项"海上稠油热采开发方案设计方法及关键技术研究"(2013-YXZHKY-013);海洋石油高效开发国家重点实验室开放基金(CCL2013RCPS0236GNN)内容

摘　　要：原油流动性差使得L16油田难以取得合格的地下含气原油样品,无法直接掌握地层原油的高压物性,流体性质具有较强的不确定性。统计分析40个国内主要稠油油藏脱气原油黏度和气油比,回归出二者之间的对数关系式。根据L16-3井脱气原油黏度计算L16油田地层原油的气油比为8.67 m3/m3。结合室内原油复配实验,进一步得出地层含气原油的饱和压力约为3.77 MPa,黏度约为10299 m Pa·s。发现带气顶的L16油田原油饱和压力远小于地层压力(11.4 MPa),存在与经典油层物理理论相悖的现象。通过对国内外同类油藏的深度调研比对,结合L16油田的自身特点,认为L16油田在长期的油水气相互作用过程中,极有可能形成具有封隔作用的沥青壳,从而将油藏形成的气顶与原油隔离开来,使得天然气难以回溶至地层原油内。表现为虽存在气顶,但原油的饱和压力却远低于地层压力,最终合理地解释了油藏流体存在的不确定性和矛盾。The bad crude oil liquid makes difficult to obtain qualified underground gas oil samples in L16 oilfield,unable to grasp the high pressure physical properties of crude oil directly,fluid property has strong uncertainty. By analyzed statistically of 40 domestic main degassed oil viscosities and gas oil ratios of heavy oil reservoir,a logarithmic relation between the two has been regressed. According to the L16-3 Wells degassed oil viscosity,oil gas ratio for natural oil in L16 oilfield formation is calculated to be 8. 67 m3 / m3.. Combined with indoor crude compound with experiment,it is concluded that formation further gas oil saturation pressure of 3. 77 MPa,viscosity is about 10299 m Pa. s. It is found that oil saturation pressure in gas caped L16 oil field is far less than the formation pressure( 11. 4 MPa),is contrary to the classical theory of reservoir physical phenomenon. Through the depth investigation and research of the same kind of reservoir at home and abroad,combined with the characteristics of L16 oilfield,it is thought that L16 oilfield is likely to form the asphalt shell having packer function in the interaction process of oil and gas for a long time,which isolates the gas cap formed by reservoir formation from the crude oil,making natural gas to be difficult to back to the solution to the formation of crude oil. As though there are gas cap,but crude oil saturation pressure is far lower than the formation pressure,which finally explained reasonably of the uncertainty and the contradiction of reservoir fluid.

关 键 词：气顶 超稠油 气油比 饱和压力 沥青壳 

分 类 号：TE353[石油与天然气工程—油气田开发工程]