低渗透稠油油藏水平井蒸汽吞吐开井阶段温度分布

Temperature distribution calculation for horizontal well with cyclic steam injection
in low-permeability heavy-oil reservoir

 孙璐¹ 刘月田¹ 葛涛涛² 陈民锋¹

中国石油大学（北京）石油工程教育部重点实验室，北京 102249 中海石油（中国）有限公司天津分公司渤海石油研究院，天津 300450）

MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, China Bohai Oilfield Research Institute, Tianjin Branch of CNOOC Ltd., Tianjin 300450, China)

 低渗透稠油油藏开采中具有明显的启动压力梯度，启动压力梯度受流度影响。在油藏注蒸汽开采过程中，压力传播将受到储层内温度分布的制约，因此，开井生产阶段储层内的加热范围和温度分布情况的研究是确定油藏蒸汽吞吐极限动用半径的基础。文中运用马克斯￣兰根海姆油藏热力学模型，建立了水平井蒸汽吞吐注汽阶段加热半径计算模型、焖井结束后加热区平均温度计算模型、开井生产加热区平均温度计算模型；在此基础上，又建立了开井生产阶段温度分布计算模型，研究了低渗透稠油油藏水平井蒸汽吞吐开采阶段加热区内温度分布特征。分析表明：相比天然能量开采，注蒸汽开采将增大水平井的极限动用半径；在水平井蒸汽吞吐生产阶段，沿着水平井段的径向方向，渗流过程转变为变启动压力梯度的流动形式，其压力传播特征与定启动压力梯度的非达西渗流特征存在不同。

 It is obvious that there is a threshold pressure gradient in the development of low-permeability heavy-oil reservoir. Pressure propagation law will be restricted by the temperature distribution within the reservoir by steam injection production. In order to determine the limit drainage radius of heavy-oil reservoir by steam stimulation, the heated range and temperature distribution are needed to study. This paper establishes the calculation models of horizontal well in cyclic steam injection with Max-Langenhai thermo-dynamics model. These models consist of steam injection heating radius calculation model, average temperature calculation model after soaking, the average temperature calculation model of heated area for production. Based on these models, the calculation model of temperature distribution in different production time is built to study the temperature distribution characteristics of heated area in different stage. The result shows that the limit drainage radius can be expanded with steam injection compared with natural reservoir energy. In the production of horizontal well with cyclic steam injection, seepage process changes to the flow of variable threshold pressure gradient from the flow of stable threshold pressure gradient. That would make the pressure transmission characteristics of the former obviously different from the later.

10.6056/dkyqt201604022