页岩气泡沫排水采气技术规范对比分析与应用

Comparative Analysis and Application of Shale Gas Foam Drainage Gas Production Technological Specification

泡沫排水采气工艺是排水采气措施的重要组成部分,已在川渝页岩气区块大规模推广应用,为进一步明确页岩气井泡排的技术要求,采取对比分析、经验分析等方法,对比分析页岩气泡排技术现行标准及规范的适用性。研究结果表明:泡排工艺现行标准及规范有效规定了泡排化学药剂检测、工艺方案设计、现场工艺装置配套等技术内容,但标准间存在重叠性、差异性、矛盾性、内容单一性等问题,无法凭借任一标准明确泡排工艺实施全过程;针对川渝页岩气平台井组整体泡沫排水采气工艺特点,2023年编制形成的NB/T11045.3—2023《页岩气排采工艺技术规范第3部分:泡沫排水》,妥善解决了现行标准间的突出差异与矛盾,涵盖了页岩气开发过程中平台井组整体泡排工艺实施全过程的技术要点;综合现行标准及规范情况,该标准仍存在一些不足,建议在消泡剂性能评价中增加“贮存稳定性”技术指标,并在泡排加注工艺流程的集中计量平台的单井起泡与集中消泡流程、投掷器投注工艺流程中增设二级消泡,进一步完善泡排技术规范内容。

Drainage foam gas production process is an important integral part of drainage gas production measure and has been used on a large scale on the shale gas block in the Sichuan-Chongqing region.To further clarify the technological requirements on shale gas foam drainage,the methods for comparative analysis and experience analysis were adopted to compare and analyze the adaptability of the current standards and specifications on shale gas foam drainage technology.The study indicates that the current foam drainage process effectively specify the technological contents,such as inspection of foam drainage chemical agents,design of process plan and the related on-the-site process facilities.However,some problems exist among the current standards,such as overlapping,differences,contradiction and singularity of content.Therefore,it is possible to clarify complete execution of foam drainage process by means of any single standard.Focusing on the overall foam water drainage gas production process characteristics of the Sichuan-Chongqing shale gas platform well patterns,the NB/T 11045.3—2023“Shale gas—Specification for drainage gas recovery technique—Part 3:Water drainage by foam”was formulated in 2023 to solve the differences and contradictions among the current standards and cover the main technological points in overall foam drainage process execution of the shale gas platform well pattern in shale gas development process.So far as the current standards and specifications are concerned,those standards still have something unsatisfactory.It is proposed to add the technical indexes of“storage stability”to functional evaluation of defoaming agents.It is also proposed to add secondary defoaming to the single-well foaming and concentrated defoaming process and the thrower injection technical process on the concentrated measurement platform of foam additional injection technical process,thus further perfecting the content of the foam drainage technological specifications.