低成本低油水比低土相油基钻井液技术研制与应用

Research on Low-Cost,Low Oil-Water Ratio,Low Soil Content Oil-based Drilling Fluid Technology

油基钻井液的应用范围较广,为降低油基钻井液成本,通过优选低成本油类基础液,开展研发新型单剂高效乳化剂,降低油水比,降低有机土加量等研究,建立了新型低成本低油水比低土相油基钻井液配方,同时对其性能进行了室内评价。实验结果表明:该钻井液油水比在65∶35~85∶15范围可调,有机土加量小于等于2.0%,密度为1.4~2.2 g/cm^(3),抗温达200℃,破乳电压大于800 V,高温高压失水量小于3 mL,油基钻井液单方成本较3号白油配制的油基钻井液降低15%以上,适用于-25℃条件,可满足辽河油区冬季施工需求。在辽河油区页岩油、致密油地层进行了应用,现场应用结果表明,低成本低油水比低土相油基钻井液性能稳定,封堵防塌性能良好,乳化稳定性良好,耐低温效果好,单方成本明显降低。研究成果有利于油基钻井液应用规模的扩大,可满足非常规油气资源低成本、安全、高效开发的技术需求。

The application range of oil-based drilling fluids is extensive.To reduce the cost of oil-based drilling fluids,a new low-cost formulation with a low oil-water ratio and low soil content was developed.This was achieved by selecting affordable oil-based base fluids,developing new single-dose high-efficiency emulsifiers,reducing the oil-water ratio,and decreasing the addition of organic soil.The performance of the new formulation was evaluated in the laboratory.According to experimental results,the oil-water ratio of the drilling fluid can be adjusted within the range of 65∶35 to 85∶15.The organic matter content is limited to 2.0%or lower,with a density of 1.4 to 2.2 g/cm 3 and temperature resistance up to 200℃.The demulsification voltage is greater than 800 v,high temperature and high pressure fluid loss is less than 3 mL,and the unit cost of oil-based drilling fluid is reduced by over 15%compared to the fluid prepared with No.3 white oil.This fluid is suitable for-25℃conditions and can meet construction needs during winter in the Liaohe Oilfield.The low-cost,low oil-water ratio,low-soil oil-based drilling fluid has been successfully applied in shale oil and tight oil formations in Liaohe Oilfield.Field application results demonstrate its stable performance,good plugging and anti-collapse capabilities,excellent emulsification stability,good low-temperature resistance,and significantly reduced unilateral cost.These research findings contribute to the expansion of the application scale of oil-based drilling fluid and can meet the technical requirements for the low-cost,safe,and efficient development of unconventional oil and gas reservoirs.