沁水盆地煤层气田地面集输技术现状与展望

沁水盆地煤层气田经过近10年的开发建设,系统建设和运行过程中"三难"(征地难、建站难、布管难)、"三高"(投资高、闲置高、能耗高)、采出水处理"三差异"(水质差异、排放标准差异、产水量差异)等问题不断凸显,现有建设模式下的降本提效措施不能解决上述问题。为此,以煤层气产能建设项目的建设与运行双重因素为出发点,在总结现有集输系统形成的主体技术和配套技术的基础上,围绕建设低成本、运行低能耗、系统高效率的核心理念,从改变现有的产能建设模式和集输系统模式入手,从井网布局、站场建设和管网设计等方面提出了新的技术思路:(1)构建分布式地面集输模式,创建新型"分布设点、双管前置、井站合建、橇装增压"总体集输工艺优化模式;(2)推进分期式地面建设理念,研究适合于站场橇装设备分期建设系数,提高设备利用率,调整采气、集气管网的设计系数,以确保系统产、输能力匹配合理;(3)推广井、站合建的橇装技术,实现工厂化预制和模块化施工,减少现场工作量,缩短建设工期,从而提高建设效率和建设质量。结论认为,现有建设模式及系统模式下的优化、调整手段不是该气田降低投资的根本出路,探索新的产能建设模式、以非常规手段解决非常规问题,才能从根本上提高系统投资回报率、提高系统的适应性。

CBM ground gathering and transportation technologies in the Qinshui Basin:Status and prospect

Over a decade of CBM development, the Qinshui Basin is now faced with more and more prominent problems in the process of system construction and operation, e.g. "three difficulties" (difficult land acquisition, difficult station construction and difficult pipeline arrangement), "three highs" (high investment, high idle capacity and high energy consumption) and "three differences" of produced water treatment (difference in water quality, difference in discharge standard and difference in water production). These problems cannot be solved only by taking the measures of cost reduction and efficiency improvement in the existing construction pattern. In this paper, the main and supporting technologies formed on the basis of existing gathering systems were summarized with the double factors of CBM productivity construction projects (i.e., construction and operation). Then, guided by the concept of low-cost construction, low-consumption operation and high-efficiency system, new technical ideas were proposed from the aspects of well pattern arrangement, station construction and pipeline network design after existing productivity construction mode and gathering system were modified. The new ideas involve three aspects. First, build a distributed ground gathering system, and set up a new overall gathering technology optimization mode characterized by "distributed point arrangement, dual-pipe preset, well-station joint construction and skid-mounted pressurization". Second, promote the concept of phased ground construction, figure out the coefficient that is suitable for the phased construction of skid-mounted equipment at stations, increase the equipment utilization ratio and adjust the design factors of gas production and gathering pipelines, so as to ensure a reasonable match between production capacity and transportation capacity of the system. Third, promote the skid-mounted technology of well-station joint construction and realize factory prefabrication and modularized construction, so as to cut down field workload, shorten construction period and consequently improve construction efficiency and quality. In conclusion, optimizing and adjusting the existing construction mode and system are not the essential solution to the investment reduction of this gas field, and the only way to increase the return on investment and improve the system adaptability essentially is to explore new productivity construction modes and solve the unconventional problems by extraordinary methods.