大型丛式水平井工程与山区页岩气高效开发模式

以水平井为基本特征的复杂结构井,包括大位移水平井、多分支水平井、"U"形井及丛式水平井等,是实现低渗透、非常规、深水、深层等复杂油气藏高效开发的先进井型,相关研究与实践在国内外已取得重大进展,有望在页岩油气高效开发中发挥重要的作用。在中国山区页岩气开发过程中,为了满足安全环保、节约用地、降本增效等基本要求,迫切需要加快创建独具特色的页岩气高效开发模式,为此提出了基于大型丛式水平井工程的山区页岩气高效开发模式及其工程技术支撑体系,建立了单个钻井平台"井工厂"可允许布置水平井的最大布井数量计算公式,阐明了大型丛式水平井工程"降本增效"的设计控制理念与关键技术内容;重点分析了大位移井技术的研究发展概况,阐明了大位移井及其钻井延伸极限的基本概念,给出了水平井大位移钻井裸眼延伸极限的预测计算方法,最后简要介绍了大位移井管柱力学与机械延伸极限研究所取得的相关成果及其工程意义。结论认为,该项研究成果遵循了油气田"地质与工程一体化"的高效开发思路,在今后山区页岩气开发工程中具有可预见的良好推广应用前景,将有助于推进中国"页岩革命"(Shale Revolution)取得新的进展。

A high-efficiency development mode of shale gas reservoirs in mountainous areas based on large cluster horizontalwell engineering

With the basic characteristics of regular horizontal wells, the so-called complex wells including horizontal extended-reach wells, multi-branch horizontal wells, U-shaped wells, cluster horizontal wells, etc., are advanced well types for the efficient development of low-permeability, unconventional, deep-water, and deep oil and gas reservoirs, which have been highly concerned all over the world. Significant progress at home and abroad has been made in relevant researches and practices and is expected to play an important role in the efficient development of shale oil and gas. To meet the basic needs of environment & safety, land conservation, costreducing and efficiencyincreasing, it is urgent to create a unique shale gas efficient development mode. Therefore, an efficient shale gas development mode for mountainous areas and an engineering technology support system are presented based on large cluster horizontal-well engineering. An equation is thus obtained for calculating the maximum number of horizontal wells arranged allowably in "well factory" on a single platform. The general research and development of large extended-reach well technology are analyzed by expounding the basic concept of a large extended-reach well and its drilling elongation limit. And a calculation method is thus established to predict the maximum measured depth of open hole in extended-reach drilling. Moreover, some relevant research results and their significance for down-hole tubular mechanics & mechanical extending limits in extended-reach drilling are also briefly introduced in this paper. The conclusions are drawn that, by following the idea of "integration of geology and engineering" in oil and gas development, these research results have a foreseeable application prospect in shale gas development in the mountainous areas in the future, and will contribute to new progress in China's "Shale Revolution" .