Rheological property of low-damage, ideal packing, film-forming amphoteric/sulfonation polymer drilling fluids
Low-permeability dense reservoirs, including micro-fractured reservoirs, are commonly characterized by high content of clay substances, high original water saturation, high sensitivity to invasive fluids, high capillary pressure, complicated structure and anisotropic, high flow-resistance and micro pore throats ete,. Generally they also have lots of natural micro fractures, probably leading to stress sensibility. Main damaging factors in such reservoirs are water-sensibility and water-blocking caused by invasive fluids during drilling and production operations. Once damaged, formation permeability can rarely recovered. Numerous studies have shown that damaging extent of water-blocking ranges from 70% to 90%. Main damaging mechanisms and influencing factors of water-blocking were systematically analyzed. Also some feasible precaution or treating approaches of water-blocking were put forward. In a laboratory setting, a new multi-functional drilling fluid composed mainly of amphion polymer, sulfonation polymer,high effectively preventive water-blocking surfactants, ideal packing temporary bridging agents (TBA) and film-forming agents, etc.,were developed. New low-damage drilling fluids has many advantages, such as good rheological properties, excellent effectiveness of water-blocking prevention, good temporary plugging effect, low filtration and ultra-low permeability (API filtration≤5 mL,HTHP filtration≤10 mL, mud cake frictional coefficients≤0.14, permeability recovery＞81%), can efficiently prevent or minimize damage, preserve natural formation and enhance comprehensive development-investment effect in TUHA Jurassic dense sandstone reservoir formation with low-permeability, the only one developing integrated condense gas field. Some references can be provided to similar reservoir formations.
low-permeability dense gas condense reservoir amphion and sulfonation polymer drilling fluid damage controlling water-blocking ideal packing theory (IPT) film-forming agent rheological properties
ZHANG Hong-xia(张洪霞) YAN Jie-nian(鄢捷年) SHU Yong(舒勇) ZHAO Sheng-ying(赵胜英)
Ministry of Education Key Laboratory of Petroleum Engineering, China University of Petroleum Beijing,Beijing 102249, China
国际会议
长沙
英文
429-433
2008-09-28（万方平台首次上网日期，不代表论文的发表时间）