【摘要】 虽然目前钻井液CO₂污染处理技术的研究成果较多,但在实际应用中仍然存在许多问题,是一个十分棘手的问题。总结了常见的CO₂污染处理方式及其不足之处。针对水基钻井液CO₂污染现象,根据污染机理提出了处理建议:保持钻井液中适度的黏土含量,使用Ca（OH）₂和CaCl₂等钙处理剂;使用抗高温抗盐的强吸附性处理剂、适当使用新浆替代老浆。介绍了XX46-X1和XX008-6-X2两口受CO₂污染井的处理情况。以XX46-X1井为例,采取的具体措施有:使用离心机控制固相含量,用真空除气器不间断在地面脱气,增大钻井液密度至2.0 g/cm³,以阻止CO₂进入流体;使用适量0.2%石灰乳冲入钻井液,补充SMP-Ⅲ、SMP-Ⅱ、高温抗盐降滤失剂RSTF、高温稀释剂HTX等处理剂及NaOH胶液;由于污染较为严重,后期配制胶液时加入适量0.5%CaCl₂配合处理。受污染钻井液按建议经过处理后,钻井液黏度、切力降低,流变性和滤失量得到控制,满足了工程需要,达到了预期目的。更多还原

【Abstract】 Many technologies handling CO₂ contamination to drilling fluids have shortages in practical use. This paper summarizes the deficiencies of the methods commonly used, and presents advices for the treatment of CO₂ contamination based on the mechanisms of contamination: drilling fluid should have moderate bentonite content, and Ca（OH）2 and Ca Cl2 should be used. High temperature saltresistant and highly adsorptive drilling fluid additives should be used, and old mud replaced with new one if necessary. Contamination of drilling fluids by CO₂ has been encounteredin drilling the wells XX46-X1 and XX008-6-X2. To cope with the CO₂ contamination in drilling the well XX46-X1, centrifuges were used to control solids content and vacuum degassers used for continuous degassing of the drilling fluid at the surface. Mud density was increased to 2.0 g/cm³ to prevent CO₂ gas cut. A proper amount of 0.2% Ca（OH）2, SMP-II, SMP-III, RSTF（high temperature salt-resistant filter loss reducer）, HTX（high temperature thinner） and Na OH solution were usedto minimize the negative effects of CO₂ on the properties of the drilling fluid. 0.5% Ca Cl2 solution was used when the CO₂ gas cut became severe in late period. With these treatment, the viscosity and gel strengths of the drilling fluid were reduced, and the rheology and filter loss controlled, satisfying the needs of engineering and achieving the desired results.更多还原