论文部分内容阅读
在水基泥浆中加入5—12%矿物油(或柴油)所形成的水包油钻井液已在胜利油田广泛应用于防止卡钻的发生。但在某些情况下,这种泥浆体系的乳化稳定性不能满足钻井作业的需要。为了克服这一缺点,研制出一种颗粒极细并具有特殊润湿性(弱亲水)的固体乳化剂,并已成功地应用于改进乳状液的稳定性和钻井液的其它性能。 在提出该项技术之前,对各种不溶于水的微细固体颗粒对水包油乳状液稳定性的影响进行了较深入的研究。这些颗粒状物质包括膨润土、有机土、高岭石粉、重晶石粉、两种颗粒尺寸不同的碳酸钙粉、两种具有不同润湿性的硅石粉以及新研制的固体乳化剂。为评价这些微粒对乳化稳定性的贡献,分别开展了乳状液稳定性实验和液滴聚并实验。使用静置12h后乳状液的体积和油/水滴的半衰期作为乳状液稳定性的评价指标。实验结果显示,对于给定的油/水体系,乳状液类型和稳定性取决于固体颗粒的类型、尺寸、浓度和润湿性,以及是否有表面活性剂存在。与其它类型的颗粒相比,固体乳化剂的微粒可为水包油乳状液提供最有效的稳定性。同时实验中发现,在某些情况下,固体乳化剂微粒还能有效地稳定油包水乳状液,因为其润湿性接近于中性。 目前,使用新研制的固体乳化剂稳定的水包油乳化泥浆已经成为胜利油田钻定向井和水平
The oil-in-water drilling fluid formed by adding 5-12% mineral oil (or diesel oil) to water-based mud has been widely used to prevent sticking in Shengli Oilfield. However, in some cases, the emulsion stability of this mud system can not meet the needs of drilling operations. In order to overcome this disadvantage, a solid emulsifier with very fine particles and a special wettability (weakly hydrophilic) has been developed and has been successfully used to improve emulsion stability and other properties of drilling fluids. Before this technique was proposed, the effects of various water-insoluble fine solid particles on the stability of oil-in-water emulsions were studied in depth. These particulate materials include bentonite, organic earth, kaolinite powder, barite powder, two calcium carbonate powders with different particle sizes, two silica powders with different wetting properties and a newly developed solid emulsifier. To evaluate the contribution of these particles to the emulsion stability, emulsion stability experiments and droplet aggregation experiments were carried out, respectively. The volume of emulsion after standing for 12 h and the half-life of oil / water droplets were used as evaluation indicators for emulsion stability. The experimental results show that for a given oil / water system, the type and stability of the emulsion depends on the type, size, concentration and wettability of the solid particles, and on the presence or absence of surfactants. In contrast to other types of particles, the particles of the solid emulsifier provide the most effective stability for oil-in-water emulsions. In the meantime, it was found in experiments that, in some cases, the solid emulsifier particles can effectively stabilize the water-in-oil emulsion because the wettability is close to neutrality. At present, the use of newly developed solid emulsifier-stabilized oil-in-water emulsified mud has become the drilling well and horizontal drilling Shengli Oilfield