LHCX凝析气田水合物形成预测及防止措施研究

天然气水合物是采气过程中经常遇到的一个重要问题。在生产过程中，水合物的生成可导致气体输送管线及加工设备的堵塞而影响正常生产。文章针对LHCX凝析油气田，对水合物的形成条件进行了论述，采用统计热力学方法对该气田不同压力条件下水合物形成的温度进行了预测，计算出了M1井、M3井不同产量条件下井口流动温度及M1井、M3井地面给定输出压力下的井口节流温降情况。根据计算结果得知：该气田气井在产量10×10₄m₃/d、压力大于5.0 MPa时，井筒中不会形成水合物；在地面给定输出压力下，M1井通过气嘴节流后的气流温度高于水合物形成温度，不会形成水合物，而M3井通过气嘴节流后的气流温度低于水合物形成温度，将形成水合物。另外，还对水合物的预防及清除方法进行了讨论，针对LHCX凝析油气田情况，建议采用加注甲醇（己二醇）和地面加热升温措施以防止水合物的形成。

PREDICTION AND COUNTERMEASURES OF HYDRATE GENERATION FOR LHCX CONDENSATE FIELD 1)

Gas hydrate is a large problem often encountered in gas recovery process. During production, hydrate generation may cause blocking of gas transmission pipelines and gas processing devices and influence the normal operation. Aiming at LHCX condensate field, the conditions of hydrate generation are discussed. With the statistical thermodynamic method, the temperature of hydrate generation is predicted under the different pressure of the gas field. The wellhead flowing temperatures are calculated for Wells M 1 and M 3 under different productions. And under the given output pressure on the ground, the temperature drop caused by throttle is calculated respectively for Wells M 1 and M 3. According to the calculating results, hydrate will not be produced in the boreholes of the gas field when the production is 10×104 m/d. and the pressure is more than 5.0 MPa for the gas wells. Under the given output pressure on the ground, hydrate will not be produced for well M 1 since the gas flowing temperature after throttle is higher than the temperature of hydrate generation, but for well M 3, hydrate will be produced since the gas flowing temperature after throttle is lower than the temperature of hydrate generation. Also, the prevention and removing method of hydrate are discussed. Aiming at the situation of LHCX condensate field, it is suggested the measures of methanol (ethylene glycol) injection and ground heating are performed to prevent hydrate generation.