Wellbore instability is an issue that,if left untreated,can cause wells to collapse,resulting in human,environmental,equipment,and revenue losses.Drilling fluids have been used to enhance the drilling process by lubri...Wellbore instability is an issue that,if left untreated,can cause wells to collapse,resulting in human,environmental,equipment,and revenue losses.Drilling fluids have been used to enhance the drilling process by lubricating and cooling the drill bit,eliminating cuttings,and most importantly,by improving the stability of the well by preventing fluid loss.However,there has been an increase in operational demands and challenges that call for drilling fluids to be more effective,economical,sustainable,and environmentally friendly.With shales that have infinitesimally small pores,nanoparticle additives in drilling fluids can be crucial in providing the properties that are necessary to prevent fluid loss and provide wellbore stability while meeting the operational demands of the present day.Therefore,this paper examines the use of nanoparticle additives including copper(Ⅱ)oxide(CuO),magnesium oxide(MgO),and aluminum oxide(Al_(2)O_(3))where they are tested under three conditions using the permeable plugging tester(PPT),high-temperature high-pressure(HTHP)fluid loss apparatus,and API low-temperature e low-pressure(LTLP)fluid loss apparatus under concentrations of 0.03%and 0.10%.Finally,based on the results,each nanoparticle sample(particle sizes between one and 100 nm)performed well in contributing to the aim of this project.CuO is the most effective inhibitor across all concentrations and under the three different conditions.It contributed to reducing the fluid loss from 37.6 mL to 18.2 and 13.2 mL,which is between 52%and 65%of fluid reduction.For MgO,it contributed to fluid loss reduction to 23.8 mL and 15 mL,which translated to 37%e60%of fluid loss reduction.The use of Al_(2)O_(3) nanoparticles resulted in a fluid loss reduction to 33.6 mL and 17.8 mL,reducing the fluid loss up to 11%,at HTHP and up to 53%at LTLP.Unlike CuO and MgO,Al_(2)O_(3) was less effective under HTHP conditions when compared to LTLP conditions.Al_(2)O_(3) did not suffer as a significant diminishing benefit with increasing concentration in LTLP conditions however which means that at a higher concentration,it may begin to be more effective.Each material used in this study has its own specific and technical characteristics that will help create a progressive amount of property,such as providing stability and withstanding the high-temperature and highpressure condition downhole.展开更多
The pressure loss of cross-flow perforated muffler has been computed with the procedure of physical modeling,simulation and data processing. Three-dimensional computational fluid dynam-ics (CFD) has been used to inves...The pressure loss of cross-flow perforated muffler has been computed with the procedure of physical modeling,simulation and data processing. Three-dimensional computational fluid dynam-ics (CFD) has been used to investigate the relations of porosities,flow velocity and diameter of the holes with the pressure loss. Accordingly,some preliminary results have been obtained that pressure loss increases with porosity descent as nearly a hyperbolic trend,rising flow velocity of the input makes the pressure loss increasing with parabola trend,diameter of holes affects little about pressure loss of the muffler. Otherwise,the holes on the perforated pipes make the air flow gently and meanly,which decreases the air impact to the wall and pipes in the muffler. A practical perforated muffler is used to illustrate the available of this method for pressure loss computation,and the comparison shows that the computation results with the method of CFD has reference value for muffler design.展开更多
The resistance loss of transportation was studied and the influences of buoyancy layout,mineral content and elastic modulus of flexible hose were investigated based on three-dimensional finite element model of fluid-s...The resistance loss of transportation was studied and the influences of buoyancy layout,mineral content and elastic modulus of flexible hose were investigated based on three-dimensional finite element model of fluid-solid interaction by MSC.MARC/MENTAT software.The numerical results show that the resistance losses increase with the increase of mineral content Cv and velocity of internal fluid v and decrease with the increase of elastic modulus E of flexible hose.The buoyancy layout and the velocity of internal fluid have greater impacts on the resistance losses than the elastic modulus of flexible hose.In order to reduce the resistance losses and improve the efficiency of the deep-ocean mining,Cv and v must be restricted in a suitable range (e.g.10%-25% and 2.5-4 m/s).Effective buoyancy layout (such as Scheme C and D) should be adopted and the suitable material of moderate E should be used for the flexible hose in deep-ocean mining.展开更多
Aiming at the problems of microfracture development in hard brittle shale gas layer in Fuling block, Chongqing, such as collapse of borehole wall and the existence of permeability loss of microfracture during drilling...Aiming at the problems of microfracture development in hard brittle shale gas layer in Fuling block, Chongqing, such as collapse of borehole wall and the existence of permeability loss of microfracture during drilling, and serious pollution of drilling environment with oil-based drilling fluid, a water-based drilling fluid system for anti-collapse and anti-leakage was studied. A water-based drilling fluid system with anti-collapse and anti-leakage was formed by introducing functional treatment agents, such as polypolysaccharide MEG, polymer emulsion film forming wall cementing agent LFGB, polyamine inhibitor LCFA and deformable particle plugging agent BXLZ, into the conventional water-based drilling fluid. After rolling at 130°C for 16 h, the system has good rheological properties, low filtration loss, good inhibition, lubrication and plugging properties. It has good plugging properties for 0.12 mm, 0.24 mm, 0.38 mm micro-cracks and 400 mD and 800 mD sand plates. The system was successfully tested on site in August 2019 in Fuling Reef Block, showing good rheological properties, solid wall plugging, and strong ability to seal and inhibit fracture expansion. There was no block falling in the drilling process, and the tripping, casing running and well cementing operations were all smooth, which provided a new technical idea and scheme for environmental protection and green drilling in Fuling shale gas exploitation.展开更多
文摘Wellbore instability is an issue that,if left untreated,can cause wells to collapse,resulting in human,environmental,equipment,and revenue losses.Drilling fluids have been used to enhance the drilling process by lubricating and cooling the drill bit,eliminating cuttings,and most importantly,by improving the stability of the well by preventing fluid loss.However,there has been an increase in operational demands and challenges that call for drilling fluids to be more effective,economical,sustainable,and environmentally friendly.With shales that have infinitesimally small pores,nanoparticle additives in drilling fluids can be crucial in providing the properties that are necessary to prevent fluid loss and provide wellbore stability while meeting the operational demands of the present day.Therefore,this paper examines the use of nanoparticle additives including copper(Ⅱ)oxide(CuO),magnesium oxide(MgO),and aluminum oxide(Al_(2)O_(3))where they are tested under three conditions using the permeable plugging tester(PPT),high-temperature high-pressure(HTHP)fluid loss apparatus,and API low-temperature e low-pressure(LTLP)fluid loss apparatus under concentrations of 0.03%and 0.10%.Finally,based on the results,each nanoparticle sample(particle sizes between one and 100 nm)performed well in contributing to the aim of this project.CuO is the most effective inhibitor across all concentrations and under the three different conditions.It contributed to reducing the fluid loss from 37.6 mL to 18.2 and 13.2 mL,which is between 52%and 65%of fluid reduction.For MgO,it contributed to fluid loss reduction to 23.8 mL and 15 mL,which translated to 37%e60%of fluid loss reduction.The use of Al_(2)O_(3) nanoparticles resulted in a fluid loss reduction to 33.6 mL and 17.8 mL,reducing the fluid loss up to 11%,at HTHP and up to 53%at LTLP.Unlike CuO and MgO,Al_(2)O_(3) was less effective under HTHP conditions when compared to LTLP conditions.Al_(2)O_(3) did not suffer as a significant diminishing benefit with increasing concentration in LTLP conditions however which means that at a higher concentration,it may begin to be more effective.Each material used in this study has its own specific and technical characteristics that will help create a progressive amount of property,such as providing stability and withstanding the high-temperature and highpressure condition downhole.
文摘The pressure loss of cross-flow perforated muffler has been computed with the procedure of physical modeling,simulation and data processing. Three-dimensional computational fluid dynam-ics (CFD) has been used to investigate the relations of porosities,flow velocity and diameter of the holes with the pressure loss. Accordingly,some preliminary results have been obtained that pressure loss increases with porosity descent as nearly a hyperbolic trend,rising flow velocity of the input makes the pressure loss increasing with parabola trend,diameter of holes affects little about pressure loss of the muffler. Otherwise,the holes on the perforated pipes make the air flow gently and meanly,which decreases the air impact to the wall and pipes in the muffler. A practical perforated muffler is used to illustrate the available of this method for pressure loss computation,and the comparison shows that the computation results with the method of CFD has reference value for muffler design.
基金Project(2006AA09Z240)supported by the National High Technology Research and Development Program of China
文摘The resistance loss of transportation was studied and the influences of buoyancy layout,mineral content and elastic modulus of flexible hose were investigated based on three-dimensional finite element model of fluid-solid interaction by MSC.MARC/MENTAT software.The numerical results show that the resistance losses increase with the increase of mineral content Cv and velocity of internal fluid v and decrease with the increase of elastic modulus E of flexible hose.The buoyancy layout and the velocity of internal fluid have greater impacts on the resistance losses than the elastic modulus of flexible hose.In order to reduce the resistance losses and improve the efficiency of the deep-ocean mining,Cv and v must be restricted in a suitable range (e.g.10%-25% and 2.5-4 m/s).Effective buoyancy layout (such as Scheme C and D) should be adopted and the suitable material of moderate E should be used for the flexible hose in deep-ocean mining.
文摘Aiming at the problems of microfracture development in hard brittle shale gas layer in Fuling block, Chongqing, such as collapse of borehole wall and the existence of permeability loss of microfracture during drilling, and serious pollution of drilling environment with oil-based drilling fluid, a water-based drilling fluid system for anti-collapse and anti-leakage was studied. A water-based drilling fluid system with anti-collapse and anti-leakage was formed by introducing functional treatment agents, such as polypolysaccharide MEG, polymer emulsion film forming wall cementing agent LFGB, polyamine inhibitor LCFA and deformable particle plugging agent BXLZ, into the conventional water-based drilling fluid. After rolling at 130°C for 16 h, the system has good rheological properties, low filtration loss, good inhibition, lubrication and plugging properties. It has good plugging properties for 0.12 mm, 0.24 mm, 0.38 mm micro-cracks and 400 mD and 800 mD sand plates. The system was successfully tested on site in August 2019 in Fuling Reef Block, showing good rheological properties, solid wall plugging, and strong ability to seal and inhibit fracture expansion. There was no block falling in the drilling process, and the tripping, casing running and well cementing operations were all smooth, which provided a new technical idea and scheme for environmental protection and green drilling in Fuling shale gas exploitation.
