Solids found in drilling fluids, particularly weighting materials, can cause significant formation damage by plugging of formation pores. This study investigates formation damage caused by using oil-based drilling fluid systems weighted by micronized ilmenite or micronized barite. Rheological properties of the oil-based-mud (OBM) systems were measured. High-pressure/high-temperature (HP/HT) static filtration experiments were conducted. A coreflood system was used to simulate dynamic conditions, allowing for drilling fluid circulation at the face of the core and measuring permeability damage. Computed-tomography (CT) scan analysis revealed formation damage and depth of solid invasion. The paper presents field applications of nondamaging micronized-ilmenite-based OBM, illustrating its advantages.

钻井液中发现的固体，特别是配重材料中的固体，可能会由于堵塞地层孔隙而造成严重的地层损坏。这项研究调查了由使用微粉化钛铁矿或微粉化重晶石加重的油基钻井液系统引起的地层损害。测量了油基泥浆（OBM）系统的流变性。进行了高压/高温（HP / HT）静态过滤实验。岩心驱油系统用于模拟动态条件，允许钻井液在岩心表面循环并测量渗透率损害。计算机断层扫描（CT）扫描分析显示了地层损伤和固体侵入深度。本文介绍了无损微粉化钛铁矿基OBM的现场应用，并说明了其优势。