气井用水合物自生热解堵剂解堵效果数值模拟

Numerical Simulation of Plug Removal Effect of a Hydrate Self-heating Plug Removal Agent for Gas Well Production

董胜伟 何爱国 班凡生 董京楠

DONG Shengwei HE Aiguo BAN Fansheng DONG Jingnan

中国石油集团工程技术研究院有限公司, 北京 昌平 102200

CNPC Engineering Technology R&D Company Limited, Changping, Beijing 102200, China

在气井生产后期井筒水合物堵塞井筒现象频发，井筒水合物解堵越发重要。针对气井井筒水合物解堵问题，根据气井水合物堵塞过程和某型自生热解堵剂特性，建立了天然气水合物堵塞段分解速率数学模型和传热数学模型。开展了井筒内水合物解堵过程仿真模拟计算，获得了不同解堵剂浓度解堵过程中井筒内温度、水体积分数等参数的分布云图，得到了不同自生热解堵剂浓度下所需解堵剂用量及解堵时间。进行了不同解堵剂浓度下解堵过程实验研究，测得了不同自生热解堵剂浓度下所需解堵剂用量及解堵时间。解堵剂用量及解堵时间的模拟计算值与实验值吻合度均大于80%。研究发现随着解堵剂浓度增加，解堵时间随之缩短，解堵剂用量随之减少。但是当解堵剂浓度超过2.0 mol/L时，其解堵效果提升幅度相对降低。

In the later period of gas well production, blockage of the wellbore hydrates occurs frequently, and it is more important to remove the blockages of wellbore hydrates. According to the gas well hydrate blockage process and the characteristics of a certain type of self-generated thermal plugging agent, aiming at the problem of gas well hydrate blockage removal, a mathematical model for the decomposition rate of the gas hydrate blockage section and a heat transfer mathematical model were established. The simulation calculation of hydrate plugging removal process in wellbore was carried out, and the distribution cloud map of temperature, water volume fraction and other parameters in the process of plugging removal with different concentrations of plug removal agent were obtained, and the amount of plugging removal agent and the plugging removal time under different concentrations of autogenous pyrolysis plugging agent were obtained. An experimental study on the deblocking process under different concentrations of deblocking agent was carried out. The amount of deblocking agent and the time required for deblocking under different concentrations of autogenous thermal deblocking agent were measured in the experiment. The simulation calculation value and experimental value of the amount of unblocking agent and the unblocking time are more than 80%. The study found that as the concentration of the plugging agent increases, the plugging time decreases and the amount of plugging agent decreases. However, when the concentration of the anti-plugging agent exceeds 2.0 mol/L, the improvement of its anti-plugging effect is relatively reduced.

10.11885/j.issn.16745086.2020.03.26.01