深水气井测试管柱内水合物沉积动态研究  

Hydrate Deposition Performance in the Test String of Deep Water Gas Well

作　　者：任冠龙 张崇 董钊 孟文波 吴江 Ren Guanlong;Zhang Chong;Dong Zhao;Meng Wenbo;Wu Jiang(CNOOC ( China) Zhanjiang Branch, Zhanjiang, Guangdong 524057, China)

机构地区：[1]中海石油(中国)有限公司湛江分公司

出　　处：《特种油气藏》2019年第3期169-174,共6页Special Oil & Gas Reservoirs

基　　金：中海油“十三五”重大专项“深水测试关键技术研究”(CNOOC-KJ 135 ZDXM 05 LTD ZJ 02)

摘　　要：针对深水气井测试管柱内水合物沉积及其对测试作业的影响程度研究不足的问题,在深水气井测试管柱内水合物生成风险区域预测的基础上,建立测试管柱内水合物生成计算模型和沉积预测模型,并以陵水深水气田S2井为例,进行了不同测试工况下测试管柱内水合物沉积厚度定量预测。研究结果表明,所建立的预测模型计算结果与室内环路实验数据的误差小于10%。现场实例应用表明,通过管柱内水合物沉积厚度判断井筒缩径率,理论计算测试2h后水合物沉积导致井筒缩径率为11%,导致井口回压下降1.78 MPa,实际测得回压下降约1.86 MPa,误差仅为4.5%。现场通过观察井口回压变化情况,及时调整水合物抑制剂注入参数,确保了测试作业的安全顺利进行。该研究对深水气井测试管柱内水合物沉积的防治具有一定的指导意义。In order to understanding the hydrate deposition in the test string and study the effect of hydrate deposi tion on test operation in deep water gas well, a hydrate formation calculation model and a deposition prediction mod el within test string were established based on the prediction of hydrate formation risk area. The Well S2 in Lingshui deep-water gasfield was taken to quantitatively predict the hydrate deposition thickness in the test string under dif ferent test conditions. Research indicates that the relative error between the model prediction and the laboratory loop experiment data is less than 10%. Field application shows that the hydrate deposition thickness within the test string can be used to determine the borehole diameter reduction rate. Theoretical calculation presents that the borehole di ameter reduction rate is 11% and the wellhead back pressure is decreased by 1.78 MPa due to the hydrate deposi tion after 2 h. The measured wellhead back pressure is 1. 86 MPa. The relative error between the model calculation and the actual measurement is only 4. 5%. The hydrate inhibitor injection is timely adjusted according to the moni toring of wellhead back pressure performance to ensure safe and smooth test operation. This research could provide certain guidance for the prevention and control of hydrate deposition within the test string of gas well.

关 键 词：深水气井 水合物沉积 测试 缩径 井口回压 

分 类 号：TE257[石油与天然气工程—油气井工程]