ABSTRACT

The complexity of reservoir conditions puts forward higher requirements for drilling fluid performance. The existing water-based drilling fluids (WBFDs) are difficult to meet the requirements at high temperature reservoirs. Oil-based drilling fluids (OBDFs) are suitable for deep and ultra-deep wells because of its good temperature resistant. In this paper, the plastic viscosity (PV), apparent viscosity (AV), yield point (YP), dynamic shear ratio, filtration loss (FL) and other properties are measured to investigate the type and concentration of bentonite, emulsifier, filtration reducer, wetting agent, and barite in the OBDF. The final formula of the OBDF is: No. 5 white oil + 4% sodium dodecyl-benzenesulfonate (SDBS) + 5% bentonite + 4% 180°C oxidized asphalt powder + 10% Tween-80 + 1.5% BaSO₄. The PV, AV, and YP of No. 5 white OBDF increase by 22.4%, 17.0%, and 12.8% respectively, also the demulsification voltage can keep above 2000 V after aging at 220°C for 24 h. Compared with the drilling fluid used in Shanxi Oilfield, the properties of the No. 5 white OBDF have greatly improved the properties. The No. 5 white OBDF preparation provides new ideas for the development of OBDFs with good temperature resistant and environmental feasibility.

摘要

储层条件的复杂性对钻井液性能提出了更高的要求。现有的水基钻井液（WBFDs）难以满足高温储层的要求。油基钻井液（OBDF）具有良好的耐温性，适用于深井和超深井。本文通过测量塑性粘度（PV）、表观粘度（AV）、屈服点（YP）、动剪切比、滤失量（FL）等性能来考察膨润土、乳化剂、降滤剂的种类和浓度。 、润湿剂和 OBDF 中的重晶石。OBDF的最终配方为：5号白油+4%十二烷基苯磺酸钠（SDBS）+5%膨润土+4%180℃氧化沥青粉+10%Tween-80+1.5%BaSO ₄. 5号白色OBDF的PV、AV、YP分别提高了22.4%、17.0%、12.8%，220℃老化24h后破乳电压仍保持在2000V以上。与山西油田使用的钻井液相比，5号白OBDF的性能有了很大的提高。5号白色OBDF制剂为开发具有良好耐温性和环境可行性的OBDFs提供了新思路。