气液常温分离工艺在涩北一号气田的应用

涩北一号气田是青海油田主力生产区块之一，从1995年开始试采。试采期间气液分离采用井口注醇、站内节流降温的低温分离工艺。随着气田开发规模的不断扩大，地层能量衰减速度加快，导致压力急剧下降，仅靠低温分离工艺已不能适应气液分离要求，必须依靠外部脱水装置进行深度脱水，导致生产运行费用急剧增加。为解决该问题，通过技术改进和理论计算，提出了站内先加热后节流常温分离工艺后，再用三甘醇脱水装置脱水的改进方案， 并在2号集气站进行了现场试验。通过试验，取消了注醇工艺，简化了操作流程，彻底解决了由于甲醇泄漏带来的安全隐患，并使综合运行费用降低了38.8%，取得了很好的经济效益和社会效益。该工艺技术的成功应用，说明在气田开发中后期，当井口压力下降，采用节流膨胀制冷无法满足天然气外输要求时，气液分离采用常温分离工艺要优于先前的低温分离工艺。

Application of Gas/Liquid Separation Technology Under Atmospheric Temperature in Sebei-1 Gas Field

Sebei 1 gas field, one of major production block for Qinghai Oilfield, started its trial production in 1995. During the primary period of production, a series of separation technology were adopted for separating gas from liquid such as methane injection at the well head, throttling inside the station, gas/liquid low temperature separation, etc. However, along with the further development in this field, the formation pressure will surely decrease sharply due to the fast depletion of the reservoir, and so gas/liquid separation can not depend on the previous low temperature separation technology any more like before, but has to rely on the dehydration device which will rapidly increase the operation fee. In order to completely solve this problem, through taking some technical measures and theoretical calculation, this study put forward a new scheme, in which gas/liquid are firstly heated at the station, then through the process of throttling and separating at atmospheric temperature, finally dehydrated in TEG dehydration device. After being tested at the No.2 gathering station, this new scheme simplified the operation procedures and gave up injecting methane avoiding possible methane leakage which happened at any time like before, in this way the overall operation fee could be saved by 38.8% by this newly reformed plan, proved to have obtained significantly social and economic benefit. Through successful application of this new technology in this field, this paper suggests gas/liquid separation at atmospheric temperature should be better than the previous low temperature separation especially when the well head pressure is decreasing and cooling after throttling can not do any help for recovering gas in the production.