盐穴储气库多步造腔流场浓度场规律  

Flow Characteristics and Concentration Field of Multi-step Construction of Salt Cavern Gas Storage

作　　者：王进超 汪志明[1,2] 曾泉树[1,2] 王俊 WANG Jin-chao;WANG Zhi-ming;ZENG Quan-shu;WANG Jun(College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]中国石油大学(北京)石油工程学院,北京102249 [2]油气资源与探测国家重点实验室(中国石油大学(北京)),北京102249

出　　处：《科学技术与工程》2024年第24期10268-10279,共12页Science Technology and Engineering

基　　金：中国石油勘探开发研究院项目(PIPED.CN-2f-2019-JS-359)。

摘　　要：盐穴储库水溶造腔过程中流场特征和浓度场分布会很大程度影响腔体的扩展和腔体最终形态,而流场特征和浓度分布无法通过技术手段进行监测。为研究盐穴水溶多阶段造腔过程中流场特征、浓度场分布及它们对腔体扩展的影响规律,基于建立的盐穴储库多场耦合流动模型进行了相关的数值模拟计算,并与金坛两口储库井进行数据对比。模拟结果与现场造腔数据相一致,验证了模型的准确性。基于模拟结果和数据,分析了水溶多阶段造腔各阶段的流场特征、浓度场分布规律,并分析流场和浓度场的分布如何影响腔体的扩展。结果表明:正循环造腔会形成一个涡流,主要起冲蚀作用,一定程度抑制溶蚀作用;反循环会形成两个涡流,下部的促进卤水排出,上部促进溶蚀作用;强制对流会引起涡流,涡流强度随腔体扩大逐渐减弱,涡流使腔内流体流动,促进了对流扩散过程,从而影响浓度场的分布,最终影响到腔体扩展,通过调整正反循环方式、管柱的位置、油垫位置及注入量可以控制腔体的形态扩展;造腔前期主要受到冲蚀作用,造腔效率高,腔体表面积小使得造腔速率较慢,腔体主要向中下部扩展;后期随着腔体扩大,主要以溶蚀作用为主,造腔速率高,腔体主要向中上部扩展。研究结果和规律对现场造腔工艺设计提供一定的理论基础,对提高现场造腔效率、优化造腔工艺参数具有指导意义。The characteristics of flow field and the brine distribution will greatly affect the cavern expansion and final cavern shape in the process of constructing salt cavern gas storage,while the flow characteristics and concentration distribution can’t be monitored by technical means.To study flow characteristics,brine concentration distribution and their impact on cavern shape expansion during the multi-step salt cavern construction,numerical simulation calculations were conducted based on the established multi-physics coupled flow model,and the results were compared with field data of two storage wells in Jintan.The simulation results were consistent with the field data,which verified the accuracy of the model.Based on the simulation results and data,the flow field characteristics and brine concentration distribution in each stage of solution mining were analyzed,and how flow characteristics and brine concentration distribution affect the cavern expansion was analyzed.The results show that there will form a vortex in cavern during positive circulation,which mainly cause erosion and inhibits dissolution during solution mining.There will form two vortices in cavern during reverse circulation.The one in lower part promoting the discharge of brine and the another one in upper part promoting dissolution Forced convection will cause vortex,and the strength of vortex will gradually decrease with the expansion of the cavern.The vortex makes the fluid flow in the cavern,and promotes the process of convection diffusion,thus affecting the distribution of brine concentration,and ultimately affecting the expansion of the cavern.The shape expansion of the cavern can be controlled by adjusting the positive and negative circulation mode,the position of the tube,the position of the oil cushion,and the injection rate.In the early stages of cavern construction,erosion plays a dominant role,which resulting in high cavern construction efficiency,resulting in a slower cavity making rate because of the small surface area of the cavern.T

关 键 词：盐穴储气库 多阶段造腔 流动特征 浓度场 腔体形态 

分 类 号：TE822[石油与天然气工程—油气储运工程]