Influence of Composition of KCl/Silicate Drilling Fluids on Rheological Properties
会议名称：《The 4th Pacific Rim Conference on Rheology》
会议日期：2005年
学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 070301[理学-无机化学]
关 键 词：Silicate-based drilling fluids Rheological properties Inhibitive character Particle size distribution
摘 要：正 The silicate-based drilling fluids have been used in the petroleum industry for a long time. Early versions of silicate-based systems exhibited very good inhibitive character. However, controlling the rheological properties of this system was quite difficult when the content of solids, especially bentonite, was relatively high. Therefore, this kind of drilling fluids had not been totally accepted by the petroleum industry for a long time. Until the last decade, the sodium silicate was used again in combination with the conventional polymer additives to provide a more effective water-base shale stabilizing system, but the rheological parameters, such as apparent viscosity （μa）, plastic viscosity （μp）, dynamic yield stress （τyd） and static yield stress （τys）, often increase to an unacceptable level with the accumulation of fine drilled cuttings during drilling *** solve this problem, a newly formulated KCl/silicate drilling fluid is developed and has been successfully applied in Block 3＆7, Sudan. Prior to its applications, abundant experiments were carried out to deal with the influence of various content ratio of KG : silicate : bentonite on the rheological properties of aqueous suspension composed of KCl, sodium silicate, bentonite and gel chemicals. The additives used include three kinds of sodium silicate with different silicate ratios, bentonite, potassium chloride, polyanionic cellulose （PAC）, barite, xanthan gum （XC）, etc. The primary purpose to run these tests was to obtain the stable formulation with adequate rheological parameters when the strongly water-sensitive shale formations are encountered. The experimental data show that the rheological parameters were dominated chiefly by the content ratio of KCl : silicate : bentonite. Therefore, the optimized proportion of KCl : silicate : bentonite is critical in the design and application of silicate-based drilling fluids. This has been proven by the field applications in Block 3＆7, Sudan. This pap