泡沫排水采气适用界限的实验研究

1)西南石油大学油气藏地质及开发工程国家重点实验室, 四川成都 610500; 2)中国石化西南油气分公司石油工程技术研究院,四川德阳618000; 3)中国石油集团川庆钻探工程有限公司,四川成都 610501

油气田开发; 泡沫排水; 可视化实验; 表面张力; 流型; 井筒压降; 持液率; 携液临界气流速

Experimental study on the applicable range of surfactant injection technology
LIU Yonghui1, WU Pengbo1, LUO Chengcheng1, LIU Tong2, NI Jie2, and WANG Hua3

1)State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan Province, P.R.China2)Petroleum Engineering Technology Institute, Southwest Oil & Gas Branch, SINOPEC, Deyang 618000, Sichuan Province, P.R.China3)CNPC Chuanqing Drilling Engineering Co. Ltd., Chengdu 610501, Sichuan Province, P.R.China

oilfield development; foam deliquification; visual experiment; surface tension; flow pattern; wellbore pressure drop; liquid holdup; critical gas velocity of liquid loading

DOI: 10.3724/SP.J.1249.2020.05490

备注

为明确各流型下泡沫排水工艺排液效果进而有效指导选井,设计一套可视化的空气-水-泡沫三相管流模拟实验装置,通过表面张力实验确定实验起泡剂浓度,开展不同气相表观流速和液相表观流速的泡沫举升效果实验.研究发现:在空气-水两相流动中加入起泡剂能够有效降低两相流动压降,显著抑制流动振荡; 随着气相表观流速的增加,泡沫对井筒中压降和持液率的降低幅度呈先增后减; 在泡沫排水有效区域内,井筒气和水搅动剧烈,促使加入的起泡剂与水充分接触产生大量泡沫,降低了井筒压降和持液率; 将携液临界气流速作为泡沫排水有效区域的气相表观流速上限,该区域的气相表观流速下限为泡状流到段塞流的转换界限,确定泡沫排水效果最佳区域气相表观流速界限为段塞流到搅动流的转换界限.泡沫排水适用界限将两相流流型转换界限与泡沫实验结果紧密结合,明确了泡沫排水适用气量界限,降低排采成本,为气田泡沫排水工艺的高效应用提供依据.

In order to clarify the drainage effect of the foam drainage process under various flow patterns and effectively guide the well selection, we design a set of visual air-water-foam three-phase pipe flow simulation experimental apparatus. At first we determine the foam concentration by surface tension experiment, and then we conduct different foam lifting experimental tests with different gas superficial velocities and liquid superficial velocities. We obtain the following results. Firstly, adding the surfactant to the gas-water two-phase flow can effectively reduce the two-phase flow pressure drop and significantly suppress the flow fluctuation. Secondly, the degree of decrease in pressure drop and liquid holdup in the wellbore increases first and then decreases with increasing of the gas flow rate. Thirdly, in the effective range of the foam lift, gas and water in the wellbore are vigorously agitated, prompting the added surfactant to fully contact with the water, thereby generating a large amount of foam, reducing the wellbore pressure drop and liquid holdup. Fourthly, the critical gas flow rate to carry the liquid is taken as the upper limit of the effective range of the foam lift. The lower limit in this range is the transition boundary from bubble flow to slug flow, and the optimal flow rate of the foam lift is determined as the transition boundary from slug flow to churn flow. In conclusion, limits of foam drainage application connect the two-phase flow pattern transition boundary with the results of foam experiments. The clarification of limits of foam drainage application will help reduce the cost of gas well deliquification and provide a theoretical basis for the efficient application of the foam drainage technology in gas fields.

·