中海油某油田天然气透平停机主因分析与处理

Main cause analysis and treatment of gas turbine shutdown in a CNOOC oilfield

LD32-2油田投产后,所安装的3台美国卡特彼勒生产的透平在使用该油田生产的天然气作为燃料的过程中发生了关停而无法正常发电,经检测发现,该油田生产的天然气中重碳烃含量超过了卡特彼勒透平对燃料气成分含量的要求。经论证确定通过采取冷却工艺降低天然气温度至略高于天然气中水的冰点及水合物形成的温度,从而达到脱除部分重碳烃的目的。方案实施后,处理后的天然气中甲烷摩尔分数提高到了73.945%,重碳烃(C5/C6的烃类)的摩尔分数降低到了2.177%(<2.5%),满足了卡特彼勒天然气透平对天然气燃料品质的要求。

After LD32-2 Oilfield was put into production,the three U.S.Caterpillar turbines that use the natural gas produced from LD32-2 Oilfield were in shutdown and not able to generate electricity normally.Through examining the composition of the natural gas used by the Caterpillar turbines,it was found out that the content of heavy carbon hydrocarbon exceeded that required by the Caterpillar turbines.Therefore,through technical argument,the cooling process was adopted to reduce the natural gas temperature to the level slightly higher than the freezing point and hydrate forming temperature,so that to remove a certain amount of the heavy carbon hydrocarbon from the natural gas.In the treated offshore gas,mole fraction of the methane raises to 73.945%,mole fraction of the heavy carbon hydrocarbon(carbon hydrocarbon C5/C6)reduces to 2.177%(<2.5%),satisfying the requirement of the Caterpillar turbines for gas quality.