塔里木盆地深层地下卤水全效开发利用新路径

A new method for full development and utilization of deep underground brine in the Tarim Basin

随着油气开采向深层、超深层进发,伴生地下卤水的合理处理成为油气田安全高效绿色开发必须关注的重要的问题,其对油气田的稳定生产、经济效益和区域环境保护都有着重要的影响。为此,以塔里木盆地中国天然气主产区之一的KS气田为例,在分析深层地下卤水处理面临挑战的基础上,提出了“一水分治、深度处理、分治回用”的深层油气田地下卤水电解全效利用新路径,并对其效益进行了系统分析。研究结果表明:①KS气田地下卤水体量大、矿化度较高,具有进一步全效开发利用的价值,气田所处区域太阳能资源丰富但目前尚未被全效利用,基于地下卤水电解全效利用新思路,可实现“废水”“废电”的联合应用;②分离所得的淡水一部分可应用于生态农业、碳汇林业和荒漠化回灌,另一部分可用于回注处理,具有良好的环保效益;③分离所得的淡水和浓缩液,可进一步进行电解水制氢和浓缩液电解获取有价金属,可实现可观的经济效益。结论认为,地下卤水电解全效开发利用在KS气田成功应用后,可推广复制到具有类似条件的其他油气田,为实现资源绿色循环利用、促进降本增效和低碳排放提供了新的思路和办法,有助于油气田的科学效益全面开发。

As oil and gas production steps into deep and ultra-deep reservoirs,the associated underground brine has a great influence on the stable production,economic benefit and regional environment protection of oil and gas fields,so its reasonable treatment becomes an important concern for the safe,efficient and green development of oil and gas fields.Taking the KS Gas Field in China's principal natural gas production area of the Tarim Basin as an example,this paper analyzes the challenges to the treatment of deep underground brine.Then,a new method for fully utilizing the deep underground brine of oil and gas fields based on electrolysis is put forward,i.e.,"separate treatment,in-depth treatment,and reinjection".In addition,its benefit is analyzed systematically.And the following research results are obtained.First,the underground brine in the KS Gas Field is large in volume with higher salinity,so it has the value of further full development and utilization.In the area where the KS Gas Field is located,there are abundant solar energy resources,which have not been utilized fully.Based on the new idea of electrolysis based full utilization of underground brine,the"waste water"and the"waste electricity"can be utilized in a combined way.Second,the separated fresh water can be partially used for ecological agriculture,carbon sequestration forestry and desert replenishment,and partially reinjected,realizing good environment protection benefit.Third,the separated fresh water can be electrolyzed to produce hydrogen,and the concentrate can be electrolyzed to produce valuable metals,achieving considerable economic benefit.In conclusion,after the successful application in the KS Gas Field,the full utilization of underground brine based on electrolysis can be popularized in the similar oil and gas fields,which provides a new idea and method for realizing green recycling of resources and promoting cost reduction&efficiency improvement and low carbon emission,so as to assist the overall scientific and benefit development of oil and gas fields.