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 pr...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 etc,.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 coefficient≤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.展开更多
致密砂岩气藏具有特殊的储层特性,在钻井施工中极易受到损害,且损害难以解除。临兴区块是典型的低孔渗-致密、低丰度、不含硫干气气藏。为防止储层损害,在该区块钻井完井液中引入了封堵剂Micro-ball和CARB,API滤失量降至5 m L以下,防塌...致密砂岩气藏具有特殊的储层特性,在钻井施工中极易受到损害,且损害难以解除。临兴区块是典型的低孔渗-致密、低丰度、不含硫干气气藏。为防止储层损害,在该区块钻井完井液中引入了封堵剂Micro-ball和CARB,API滤失量降至5 m L以下,防塌、封堵性能优良,对易坍塌地层的岩屑回收率大于93%。纳米微球聚合物封堵剂Micro-ball是一种纳米级高分子聚合物,能对储层的微小喉道形成暂堵,可形成超低渗透率的内泥饼;多级惰性封堵剂CARB是一种粒径多级分布的可酸溶的惰性处理剂,其粒径范围一般大于储层孔喉,其在井壁表面可快速形成薄而脆的外泥饼,封堵效果好,泥饼易于清除。LX-xx5-1H井水平段采用裸眼-压裂方式完井,施工中该体系保持了良好的润滑性能,有效解决了钻进托压问题,未出现任何黏附钻具的情况;有良好的抗污染能力,性能稳定,维护简单;具有良好的流型和强抑制性,未发生坍塌掉块情况,多次起下钻十分顺利;压裂试气产量达到预期效果。展开更多
针对河南省海陆过渡相页岩气地层特征,以及钻井工程中面临的技术难点,通过低自由水络合技术和微纳米封堵技术,构建出适合海陆过度相页岩气地层钻井的水基钻井液体系。实验评价表明该体系具有良好流变性,抑制性强,钻屑回收率达到95%以上...针对河南省海陆过渡相页岩气地层特征,以及钻井工程中面临的技术难点,通过低自由水络合技术和微纳米封堵技术,构建出适合海陆过度相页岩气地层钻井的水基钻井液体系。实验评价表明该体系具有良好流变性,抑制性强,钻屑回收率达到95%以上,线性膨胀率仅为6%左右;滤失造壁性好,HTHP滤失量小于10 m L;储层保护效果好,污染后岩心切片0.5 cm,渗透率恢复值达到90%左右,能够满足海陆过渡相页岩气钻井工程需要。展开更多
基金Project(50574061) supported by the National Natural Science Foundation of China
文摘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 etc,.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 coefficient≤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.
文摘致密砂岩气藏具有特殊的储层特性,在钻井施工中极易受到损害,且损害难以解除。临兴区块是典型的低孔渗-致密、低丰度、不含硫干气气藏。为防止储层损害,在该区块钻井完井液中引入了封堵剂Micro-ball和CARB,API滤失量降至5 m L以下,防塌、封堵性能优良,对易坍塌地层的岩屑回收率大于93%。纳米微球聚合物封堵剂Micro-ball是一种纳米级高分子聚合物,能对储层的微小喉道形成暂堵,可形成超低渗透率的内泥饼;多级惰性封堵剂CARB是一种粒径多级分布的可酸溶的惰性处理剂,其粒径范围一般大于储层孔喉,其在井壁表面可快速形成薄而脆的外泥饼,封堵效果好,泥饼易于清除。LX-xx5-1H井水平段采用裸眼-压裂方式完井,施工中该体系保持了良好的润滑性能,有效解决了钻进托压问题,未出现任何黏附钻具的情况;有良好的抗污染能力,性能稳定,维护简单;具有良好的流型和强抑制性,未发生坍塌掉块情况,多次起下钻十分顺利;压裂试气产量达到预期效果。
文摘针对河南省海陆过渡相页岩气地层特征,以及钻井工程中面临的技术难点,通过低自由水络合技术和微纳米封堵技术,构建出适合海陆过度相页岩气地层钻井的水基钻井液体系。实验评价表明该体系具有良好流变性,抑制性强,钻屑回收率达到95%以上,线性膨胀率仅为6%左右;滤失造壁性好,HTHP滤失量小于10 m L;储层保护效果好,污染后岩心切片0.5 cm,渗透率恢复值达到90%左右,能够满足海陆过渡相页岩气钻井工程需要。
