地层环境响应封堵材料研究与应用

Study and Application of Formation Environment Responsive Plugging Material

针对现有井壁稳定材料难以精准匹配地层微裂缝,缺乏地层识别和选择性作用的能力,提出了地层环境响应井壁稳定材料研发技术思路。通过建立基于地层环境因素驱动的响应机制,优化地层环境下活性组分的反应形式和形态变化,活性组分与载体材料的组装方式,设计研发出地层环境响应封堵材料SMFG-1。该产品表现出优异的地层响应性能和极佳的配伍性能,显著改善泥饼质量且环保无毒,pH值敏感范围为6~8之间,可在地层中快速响应形成沉淀,封堵地层孔喉和微裂缝,具有响应释放灵敏性和可控性。6次pH响应循环后,释放析出率仍高达99.55%。SMFG-1在北XY-HF井复杂井段成功现场应用中,提高钻井液的封堵能力、稳定井壁,成功解决硬脆性泥岩发育、裂隙发育、易垮塌掉块等井壁失稳难题,保障复杂井段钻井安全。

The borehole wall stabilizing materials presently in use have particle sizes that are unable to accurately match the sizes of micro-fractures in the formations drilled and lack the ability to identify the formation with fractures to plug and the required selective action.A technical clue for developing formation environment responsive borehole wall stabilizing materials is presented to solve these problems.A responsive mechanism based on driving factors that are formation-related is established for the purpose of optimizing the reaction form,the morphological change of the active components in formation environment and the assembling methods of the active components and the carrier materials.Based on these studies,a formation environment responsive plugging material,SMFG-1,was developed.SMFG-1 has excellent formation responsive performance and compatibility with other drilling fluid components,it remarkably improves the quality of mud cakes,and is environmentally friendly.The pH of SMFG-1 is 6-8.SMFG-1 can form sediments in formation through quick responsiveness,thereby plugging pore throats and microfractures.SMFG-1can release particles to plug microfractures with great sensitivity under controllable manner.After six pH response cycles,the release rate is still as high as 99.55%.SMFG-1 has been successfully used in drilling the complex hole section of the well Bei-XY-HF.As a result of using the SMFG-1 plugging agent,the plugging capacity of the drilling fluid was improved,and the borehole wall was stabilized.The problems encountered in drilling the easy-to-collapse hard and brittle shales with fractures and cracks were avoided and the safety of drilling the complex hole section was achieved.