We investigated the psychological effects of nail treatments on children living in child welfare facilities.We performed a single nail treatment on children living in child welfare facilities.As a result,we found that...We investigated the psychological effects of nail treatments on children living in child welfare facilities.We performed a single nail treatment on children living in child welfare facilities.As a result,we found that feelings of“energy”,“relaxation”,and“comfort”tended to increase more strongly after the treatment than before.Furthermore,these feelings increased even more after the nail treatment.The effects of nail treatments were unrelated to gender or previous nail experience.Furthermore,nail treatments increased communication and interaction with facility staff and other children residing in the facility,promoting self-expression,and,as a result,increasing a sense of accomplishment,acceptance from others,and self-esteem.This suggests that positive emotions persisted even after nail treatments,leading to positive changes in daily life.展开更多
Wellbore instability is a critical challenge in drilling operations,especially in shale formations where interaction with water-based drilling fluids can result in significant operational risks and increased costs.To ...Wellbore instability is a critical challenge in drilling operations,especially in shale formations where interaction with water-based drilling fluids can result in significant operational risks and increased costs.To address these issues,shale chemical inhibitors have become a crucial component in drilling fluid formulations to ensure wellbore integrity.Although several researchers have published some reviews on shale inhibitors,the latest advancements in shale chemical inhibitors over the past five years still warrant further discussion and summary.This literature review provided a comprehensive examination of wellbore instability,focusing on the patterns of instability encountered in drilling and the various shale chemical inhibitors employed to mitigate these issues.The review explored the utilization of shale inhibitors in water-based drilling fluids,and the discussion highlights the timeline evolution of these inhibitors,from traditional salts and polymers to advanced ionic liquids and deep eutectic solvents.Additionally,the mechanisms of shale chemical inhibitors are summarized to guide their application.The objective of this paper is to provide a detailed review of the development of shale chemical inhibitors in water-based drilling fluids,aiming to fully appreciate shale hydration inhibition methods and to provide insights into the selection and optimization of shale inhibitors to improve wellbore stability in challengingdrilling environments.展开更多
As the global exploration and development of oil and gas resources advances into deep formations,the harsh conditions of high temperature and high salinity present significant challenges for drilling fluids.In order t...As the global exploration and development of oil and gas resources advances into deep formations,the harsh conditions of high temperature and high salinity present significant challenges for drilling fluids.In order to address the technical difficulties associated with the failure of filtrate loss reducers under high-temperature and high-salinity conditions.In this study,a hydrophobic zwitterionic filtrate loss reducer(PDA)was synthesized based on N,N-dimethylacrylamide(DMAA),2-acrylamido-2-methylpropane sulfonic acid(AMPS),diallyl dimethyl ammonium chloride(DMDAAC),styrene(ST)and a specialty vinyl monomer(A1).When the concentration of PDA was 3%,the FLAPI of PDA-WBDF was 9.8 mL and the FLHTHP(180℃,3.5 MPa)was 37.8 mL after aging at 240℃for 16 h.In the saturated NaCl environment,the FLAPI of PDA-SWBDF was 4.0 mL and the FLHTHP(180℃,3.5 MPa)was 32.0 mL after aging at 220℃ for 16 h.Under high-temperature and high-salinity conditions,the combined effect of anti-polyelectrolyte and hydrophobic association allowed PDA to adsorb on the bentonite surface tightly.The sulfonic acid groups of PDA increased the negative electronegativity and the hydration film thickness on bentonite surface,which enhanced the colloidal stability,maintained the flattened lamellar structure of bentonite and formed an appropriate particle size distribution,resulting in the formation of dense mud cakes and reducing the filtration loss effectively.展开更多
Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge....Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge.Herein,inspired by the human muscle,an anisotropic fire safety aerogel(ACMCA)with precise self-actuated temperature monitoring performance is developed by combining aramid nanofibers with eicosane/MXene to form an anisotropically oriented conductive network.By combining the two synergies of the negative temperaturedependent thermal conductive eicosane,which induces a high-temperature differential,and directionally ordered MXene that establishes a conductive network along the directional freezing direction.The resultant ACMCA exhibited remarkable thermoelectric properties,with S values reaching 46.78μV K^(−1)andκvalues as low as 0.048 W m^(−1)K^(−1)at room temperature.Moreover,the prepared anisotropic aerogel ACMCA exhibited electrical responsiveness to temperature variations,facilitating its application in intelligent temperature monitoring systems.The designed anisotropic aerogel ACMCA could be incorporated into the firefighting clothing as a thermal barrier layer,demonstrating a wide temperature sensing range(50-400℃)and a rapid response time for early high-temperature alerts(~1.43 s).This work provides novel insights into the design and application of temperature-sensitive anisotropic aramid nanofibers aerogel in firefighting clothing.展开更多
In this study, hydrothermal carbon nanospheres(HCNs) were prepared by hydrothermal carbonization using glucose as the precursor, and introduced to improve the properties of water-based drilling fluid for the first tim...In this study, hydrothermal carbon nanospheres(HCNs) were prepared by hydrothermal carbonization using glucose as the precursor, and introduced to improve the properties of water-based drilling fluid for the first time. The variation in rheological and filtration characteristics of water-based drilling fluid with varying concentrations of HCNs were compared between the cases before and after thermal aging. The results demonstrated that HCNs had little influence on the rheological properties of bentonite base mud,but could effectively reduce its filtration loss after thermal aging at 220℃ For polymer-based drilling fluid, HCNs also exhibited minor influence on the rheology. The H-B model was the best fitting model for the rheological curves before thermal aging. After hot rolling at 220℃,the viscosity retention rate increased from 29% to 63%-90% with addition of HCNs, and the filtration loss decreased by 78% with 1.0w/v% HCNs. Meanwhile, the polymer-based drilling fluid with 0.5 w/v% HCNs maintained relatively stable rheology and low filtration loss after statically thermal aging at 200℃ for 96 h. For a bentonitefree water-based drilling fluid prepared mainly with modified natural polymers, the viscosity retention increased from 21% to 74% after hot rolling at 150℃ with 0.5 w/v% HCNs, and was further improved when HCNs and potassium formate were used in combination. The mechanism study revealed that,HCNs could trap dissolved oxygen, scavenge the free radicals and cross link with polymers, which prevented thermal oxidative degradation of polymers and improved the thermal stability of water-based drilling fluid. Meanwhile, HCNs could inhibit clay hydration and swelling in synergy with partially hydrolyzed polyacrylamide by physically sealing the micropores, contributing to shale formation stability.Furthermore, HCNs could effectively improve the lubrication and anti-wear performance of drilling fluid.This study indicated that HCNs could act as green, sustainable, and versatile additives in water-based drilling fluid.展开更多
This study examined the positive changes that water-based nail treatments can bring to emotions and behavior in children who do not attend school and use a place for school-refusing children.Children who do not attend...This study examined the positive changes that water-based nail treatments can bring to emotions and behavior in children who do not attend school and use a place for school-refusing children.Children who do not attend school and use a place for school-refusing children were given water-based nail treatments about once a week for three months.In addition,the parents of these children were asked to respond to questions about their children’s daily activities.The results showed that natural communication through nail treatments significantly increased positive emotions.However,continued nail treatments did not reduce the children’s problem behaviors.Some children returned to school,while others continued not attending school.Increased frequency of visits and number of treatments confirmed the promotion of communication.It was suggested that building positive relationships with family and supporters is important for achieving sustained effects from nail treatments.This study showed that nail treatments are a useful tool for promoting positive emotions,self-acceptance,and social skills,and may contribute to the emotional growth and social interest of children who do not attend school.展开更多
Forest fires pose a significant threat to human life and property,so the utilization of unmanned aircraft systems provides new ways for forest firefighting.Given the constrained load capacities of these aircraft,aeria...Forest fires pose a significant threat to human life and property,so the utilization of unmanned aircraft systems provides new ways for forest firefighting.Given the constrained load capacities of these aircraft,aerial refueling becomes crucial to extend their operational time and range.In order to address the complexities of firefighting missions involving multi-receiver and multi-tanker deployed from various airports,first,a fuel consumption calculation model for aerial refueling scheduling is established based on the receiver path.Then,two distinct methods,including an integrated one and a decomposed one,are designed to address the challenges of establishing refueling airspace and allocating tasks for tankers.Both methods aim to optimize total fuel consumption of the receivers and tankers within the aerial refueling scheduling framework.The optimization problem is established as nonlinear optimization models along with restrictions.The integrated method seamlessly combines refueling rendezvous point scheduling and tanker task allocation into unified process.It has a complete solution space and excels in optimizing total fuel consumption.The decomposed method,through the separation of rendezvous point scheduling and task allocation,achieves a reduced computational complexity.However,this comes at the cost of sacrificing optimality by excluding specific feasible solutions.Finally,numerical simulations are carried out to verify the feasibility and effectiveness of the proposed methods.These simulations yield insights crucial for the practical engineering application of both the integrated and decomposed methods in real-world scenarios.This comprehensive approach aims to enhance the efficiency of forest firefighting operations,mitigating the risks posed by forest fires to human life and property.展开更多
Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of th...Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of the water-based aerosol is always unsatisfactory due to the rapid evaporation and sedimentation of the aerosol droplets.Great efforts have been devoted to improve the stability of water-based aerosol by using additives with different composition and proportion.However,the lack of the criterion and principle for screening the effective additives results in excessive experimental time consumption and cost.And the stabilization time of the aerosol is still only 30 min,which could not meet the requirements of the perdurable interference.Herein,to improve the stability of water-based aerosol and optimize the complex formulation efficiently,a theoretical calculation method based on thermodynamic entropy theory is proposed.All the factors that influence the shielding effect,including polyol,stabilizer,propellant,water and cosolvent,are considered within calculation.An ultra-stable water-based aerosol with long duration over 120 min is obtained with the optimal fogging agent composition,providing enough time for fighting the electro-optic weapon.Theoretical design guideline for choosing the additives with high phase transition temperature and low phase transition enthalpy is also proposed,which greatly improves the total entropy change and reduce the absolute entropy change of the aerosol cooling process,and gives rise to an enhanced stability of the water-based aerosol.The theoretical calculation methodology contributes to an abstemious time and space for sieving the water-based aerosol with desirable performance and stability,and provides the powerful guarantee to the homeland security.展开更多
The environmental hazards and"carbon footprint"of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and ...The environmental hazards and"carbon footprint"of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and animals.This paper explored for the first time the interaction mechanism between natural rubber latex(NRL)and bentonite suspensions(BTs)through a series of characterization experiments,as well as the potential applications in water-based drilling fluids(WBDF).The gel viscoelasticity experiments showed that NRL could decrease the consistency coefficient(k)and flow index(n)of BTs,and enhance the shear thinning performance of BTs as pseudo-plastic fluids.In addition,0.5 w/v%NRL not only increased the critical yield stress and strengthened the structural strength between the bentonite particles,but also facilitated the compatibility of pressure loss and flow efficiency.The evaluation of colloidal stability and WBDF performance indicated that NRL particles could promote the hydration and charge stability on the surface of BTs particles,and optimize the particle size distribution and flow resistance of WBDF under the"intercalation-exfoliation-encapsulation"synergistic interaction.Moreover,NRL can improve the rheological properties of WBDF at high temperatures(<150.C),and form a dense blocking layer by bridging and sealing the pores and cracks of the filter cake,which ultimately reduces the permeability of the cake and the filtration loss of WBDF.展开更多
This study tested a chain mediation model on whether hopelessness and nostalgia play a mediating role in psychache and suicidal ideation of firefighters.A total of 652 firefighters participated in the survey(male=94.9...This study tested a chain mediation model on whether hopelessness and nostalgia play a mediating role in psychache and suicidal ideation of firefighters.A total of 652 firefighters participated in the survey(male=94.94%;mean age=23.71 years,SD=4.18 years).The firefighters completed the Chinese Revised Psychache Scale(PAS),Beck Hopelessness Scale(BHS),Southampton Nostalgia Scale(SNS),and Columbia-Suicide Severity Rating Scale(CSSRS).The path analysis results indicated that psychache positively predicted suicidal ideation.Hopelessness plays a significant mediating role between psychache and suicidal ideation further strengthening this relationship.In contrast,nostalgia mediates and weakened the relationship between psychache and suicidal ideation.Hopelessness and nostalgia jointly constructed a chain mediating effect between psychache and suicidal ideation,for higher suicidal ideation with higher hopelessness and lower nostalgia.The findings align with the Three-Step Theory of Suicide,which proposes that suicidal ideation results from the combination of pain and hopelessness and that connectedness is a key protective factor against escalating ideation.Therefore,interventions to reduce suicidal ideation in firefighters should aim to enhance their nostalgia,while reducing sense of hopelessness.展开更多
Background:Community-based first responders face high levels of workplace stressors that can pro-foundly impact their physical and mental health.Mindfulness-based interventions have shown promise in decreasing stress ...Background:Community-based first responders face high levels of workplace stressors that can pro-foundly impact their physical and mental health.Mindfulness-based interventions have shown promise in decreasing stress and increasing psychological resilience;however,implementation is difficult due to unpredictability of the job,department culture,and generational preferences.The objective of this qualitative study was to identify and enhance understanding of the specific needs and potential barriers and facilitators for the implementation of mindfulness-based programming for community-based first responders.Methods:A phenomenological qualitative study design was used to gain insights into the lived experiences of first responders and elicit perceptions regarding barriers and facilitators for engaging in mindfulness activities.During virtual semi-structured interviews,eleven career firefighters and emergency medical service(EMS)providers offered feedback relative to worksite mindfulness practices,and the use of a stress reduction smartphone application.The Consolidated Framework for Implementation Research was used to guide the analysis relative to barriers and facilitators of implementation success and sustainability.Results:First responders expressed openness to mindfulness-based interventions and a smartphone app that would provide stress reduction content,however,they were adamant that programming needed to be accessible and easily integrated into their workday.They also reinforced that organizational culture and leadership support for their health and well-being were overarching factors essential for implementation success.Conclusions:First responders were supportive of evidence-based mindfulness practices,optimally developed and/or facilitated by someone with intimate knowledge of their unique work environments and challenges.Organizational culture and leadership support were essential for implementation success and sustainability.展开更多
The wear behaviors of steel-steel pair on condition of a water-based lubricant with copolymer of acylamino polyoxyethylene polyoxypropylene ether(KE-1)included as additives are investigated with the help of the univer...The wear behaviors of steel-steel pair on condition of a water-based lubricant with copolymer of acylamino polyoxyethylene polyoxypropylene ether(KE-1)included as additives are investigated with the help of the universal micro-tribotester.Tests on friction and wear are carried out.As a reference,some tests with pure water are also performed for comparison.The results show that the prepared water-based lubricant has a good effect on the characteristics associated with friction reducing and anti-wear processes,which lay some credence to its utilization in practical industrial tribo-systems.展开更多
Drilling fluids face failure during drilling deep reservoir with high temperature and high salt.The experimental results show that high temperature and salinity reduce the negative charge on the surface of bentonite i...Drilling fluids face failure during drilling deep reservoir with high temperature and high salt.The experimental results show that high temperature and salinity reduce the negative charge on the surface of bentonite in the drilling fluid and cause the coalescence of bentonite particles.As a result,the particles coalesce,the grid structure is destroyed,and the rheological properties,rock-carrying capacity and filtration properties are lost.To resolve the foregoing,in this study,0.05-wt%carbon nanotubes are introduced into a 4%bentonite drilling fluid under conditions where the temperature and concentration of added Na Cl reach 180°C and 10 wt%,respectively.The carbon nanotubes adsorb on the bentonite surface and increase the space among bentonite particles.The steric hindrance prevents the coalescence of bentonite in high temperature and high salt environment.Thus bentonite maintains the small size distribution of bentonite and supports the bentonite grid structure in the drilling fluid.As a result,the rock-carrying capacity of the drilling fluid increases by 85.1%.Moreover,the mud cake formed by the accumulation of small-sized bentonite particles is dense;consequently,the filtration of bentonite drilling fluid reduced by 30.2%.展开更多
The demand for non-toxic and biodegradable shale inhibitors is growing in the drilling industry.In this paper,the effect of notoginsenoside(NS)as a new,environmentally friendly inhibitor of shale hydration is systemat...The demand for non-toxic and biodegradable shale inhibitors is growing in the drilling industry.In this paper,the effect of notoginsenoside(NS)as a new,environmentally friendly inhibitor of shale hydration is systematically studied for the first time.The inhibition performance of NS was evaluated via inhibition evaluation tests,including mud ball immersion tests,linear expansion tests,shale rolling recovery tests,and compressive strength tests.The inhibition mechanism of NS was analyzed using Fourier transform infrared spectroscopy(FTIR),contact angle measurements,particle size distribution determination,thermogravimetric analysis(TGA),and scanning electron microscopy(SEM).The experimental results demonstrate that NS is able to adhere to the clay surface,forming a hydrophobic film that prevents the entry of water molecules and inhibiting the hydration dispersion of the clay.Because of this,NS can maintain the original state of bentonite pellets in water,which can effectively reduce the swelling rate of bentonite,increase the recovery rate of shale drill cuttings,maintain the strength of the shale,and therefore maintain the stability of the borehole wall during drilling.In addition,NS is non-toxic,degradable,and compatible with water-based drilling fluids.The above advantages make NS a promising candidate for use as an environmentally friendly shale inhibitor.展开更多
To maintain tight control over rheological properties of high-density water-based drilling fluids, it is essential to understand the factors influencing the theology of water-based drilling fluids. This paper examines...To maintain tight control over rheological properties of high-density water-based drilling fluids, it is essential to understand the factors influencing the theology of water-based drilling fluids. This paper examines temperature effects on the rheological properties of two types of high-density water-based drilling fluids （fresh water-based and brine-based） under high temperature and high pressure （HTHP） with a Fann 50SL rheometer. On the basis of the water-based drilling fluid systems formulated in laboratory, this paper mainly describes the influences of different types and concentration of clay, the content of a colloid stabilizer named GHJ-1 and fluid density on the rheological parameters such as viscosity and shear stress. In addition, the effects of aging temperature and aging time of the drilling fluid on these parameters were also examined. Clay content and proportions for different densities of brine-based fluids were recommended to effectively regulate the rheological properties. Four theological models, the Bingham, power law, Casson and H-B models, were employed to fit the rheological parameters. It turns out that the H-B model was the best one to describe the rheological properties of the high-density drilling fluid under HTHP conditions and power law model produced the worst fit. In addition, a new mathematical model that describes the apparent viscosity as a function of temperature and pressure was established and has been applied on site.展开更多
Water-based drill cuttings(WBDC)and bauxite are used as raw materials to prepare proppants with low density and high performance.The effects of sintering temperature,sintering period,mixture ratios of materials,doping...Water-based drill cuttings(WBDC)and bauxite are used as raw materials to prepare proppants with low density and high performance.The effects of sintering temperature,sintering period,mixture ratios of materials,doping with iron oxide,and acid modification of WBDC on the properties of proppants are discussed.The proppant performance is evaluated according to the national standard SY/T5108-2014.The morphology of the proppant is analyzed using scanning electron microscopy(SEM).The crystal phase structure of the proppant is studied using X-ray diffraction(XRD).Thermal analysis of the proppant sintering process is performed using thermogravimetry(TG).Proppant Z-23 completely satisfied the SY/T5108-2014 standard.This study provides a new perspective for the resource utilization of water-based drill cuttings and preparation of low-density proppants.展开更多
Considering the increasing environmental pressure,environmentally friendly and high-performance water-based drilling fluids(WBDFs)have been widely studied in recent years to replace the commonly used oil-based drillin...Considering the increasing environmental pressure,environmentally friendly and high-performance water-based drilling fluids(WBDFs)have been widely studied in recent years to replace the commonly used oil-based drilling fluids(OBDFs).However,few of these drilling fluids are entirely composed of natural materials,which makes it difficult to achieve real environmental protection.Using laponite nanoparticles and various derivatives of natu ral mate rials,including cro sslinked starch,cellulose composite,gelatin ammonium salt,poly-l-arginine,and polyanionic cellulose,a kind of environmentally friendly water-based drilling fluid(EF-WBDF)was built for drilling in environment-sensitive areas.The properties of this EF-WBDF were evaluated by thermal stability tests on rheology,filtration,inhibition,and salt contamination.Besides,biological toxicity,biodegradability,heavy mental content and wheat cultivation tests were conducted to investigate the environmental factor of EF-WBDF.Results showed that EF-WBDF displayed satisfactory thermal resistance up to 150℃,and the rheological properties did not suffer significant fluctuation,showing potential application in high-temperature wells.The optimal rheological model of EF-WBDF was Herschel-Bulkley model.This EF-WBDF performed an eligible filtration of 14.2 mL at 150℃and a differential pressure of 3.5 MPa.This fluid could still maintain colloidal stability after being contaminated by 7.5%NaCl or 0.5%CaC1_(2).Meanwhile,rather low clay swelling degree of 2.44 mm and high shale recovery of more than 95%ensured the inhibitive capability of EF-WBDF.Furthermore,EF-WBDF presented a half maximal effective concentration(EC_(50))of51200 mg/L and a BOD/COD ratio of 47.55%,suggesting that EF-WBDF was non-toxic and easily biodegradable.The wheat cultivated in EF-WBDF could grow healthily,beneficial for reducing the adverse impact on ecological environment.The formed EF-WBDF has a promising future for drilling in environment-sensitive and high-temperature areas.展开更多
Underground mine fire always exists since the mining activity was practiced.It poses a severe safety hazard to the mine workers and may also cause a tremendous economic loss to the mines.Methods for controlling and ex...Underground mine fire always exists since the mining activity was practiced.It poses a severe safety hazard to the mine workers and may also cause a tremendous economic loss to the mines.Methods for controlling and extinguishing fires in underground mine have long been studied and there have been significant improvements.In order to know clearly about the firefighting technology used,this paper summarizes most of the underground mine firefighting methods used in the United States the past 150 years.This paper describes not only the accepted firefighting theories,but also the technologies,both direct and indirect attacking,in accordance to regulations or codes,with special attention is given to the indirect attack method and its related technologies.Further research needed is also briefly discussed at the end of this paper.展开更多
Wellbore instability,especially drilling with water-based drilling fluids(WBDFs)in complex shale for-mations,is a critical challenge for oil and gas development.The purpose of this paper is to study the feasibility of...Wellbore instability,especially drilling with water-based drilling fluids(WBDFs)in complex shale for-mations,is a critical challenge for oil and gas development.The purpose of this paper is to study the feasibility of using hydrophobically modified silica nanoparticle(HMN)to enhance the comprehensive performance of WBDFs in the Xinjiang Oilfield,especially the anti-collapse performance.The effect of HMN on the overall performance of WBDFs in the Xinjiang Oilfield,including inhibition,plugging,lu-bricity,rheology,and filtration loss,was studied with a series of experiments.The mechanism of HMN action was studied by analyzing the changes of shale surface structure and chemical groups,wettability,and capillary force.The experimental results showed that HMN could improve the performance of WBDFs in the Xinjiang Oilfeld to inhibit the hydration swelling and dispersion of shale.The plugging and lubrication performance of the WBDFs in the Xinjiang Oilfield were also enhanced with HMN based on the experimental results.HMN had less impact on the rheological and filtration performance of the WBDFs in the Xinjiang Oilfield.In addition,HMN significantly prevented the decrease of shale strength.The potential mechanism of HMN was as follows.The chemical composition and structure of the shale surface were altered due to the adsorption of HMN driven by electrostatic attraction.Changes of the shale surface resulted in significant wettability transition.The capillary force of the shale was converted from a driving force of water into the interior to a resistance.In summary,hydrophobic nanoparticles presented afavorable application potential for WBDFs.展开更多
Basil seed,containing anionic heteropolysaccharides in its outer pericarp,swells as gelatinous hydrocolloid when soaked in water.In this study,basil seed powder(BSP)was used as a multifunctional additive for water-bas...Basil seed,containing anionic heteropolysaccharides in its outer pericarp,swells as gelatinous hydrocolloid when soaked in water.In this study,basil seed powder(BSP)was used as a multifunctional additive for water-based drilling fluids.The chemical composition,water absorbency,rheological properties of aqueous suspension of BSP were tested.The effect of BSP on the rheological and filtration of bentonitebased drilling fluid before and after thermal aging was investigated.The inhibition characteristics were evaluated by linear swelling,shale cuttings dispersion and shale immersion test.Lubricity improvement by BSP was measured with extreme pressure lubricity test.The results revealed that incorporation of BSP into bentonite suspension improved rheological and filtration properties effectively after thermal aging of 120℃.BSP exhibited superior inhibitive capacity to xanthan and synergistic effect with KCl.BSP could reduce friction by forming hydration layer.The nanoscale three-dimensional network structures enable BSP to maintain high water retention and absorb strongly on bentonite and metal surface,contributing to enhanced rheology,filtration,inhibition and lubrication properties.The versatile characteristic of BSP,as well as biodegradation makes it a promising additive using in high performance water-based drilling fluid and a potential alternative to conventional synthetic polymers.展开更多
基金This study received a research grant from the Hoyu Science Foundation in 2023.
文摘We investigated the psychological effects of nail treatments on children living in child welfare facilities.We performed a single nail treatment on children living in child welfare facilities.As a result,we found that feelings of“energy”,“relaxation”,and“comfort”tended to increase more strongly after the treatment than before.Furthermore,these feelings increased even more after the nail treatment.The effects of nail treatments were unrelated to gender or previous nail experience.Furthermore,nail treatments increased communication and interaction with facility staff and other children residing in the facility,promoting self-expression,and,as a result,increasing a sense of accomplishment,acceptance from others,and self-esteem.This suggests that positive emotions persisted even after nail treatments,leading to positive changes in daily life.
基金supported by the Research Foundation of China University of Petroleum-Beijing at Karamay(No.XQZX20250032)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2022D01A250)the Basic Research Foundation of Xinjiang Uygur Autonomous Region(No.XQZX20250003)。
文摘Wellbore instability is a critical challenge in drilling operations,especially in shale formations where interaction with water-based drilling fluids can result in significant operational risks and increased costs.To address these issues,shale chemical inhibitors have become a crucial component in drilling fluid formulations to ensure wellbore integrity.Although several researchers have published some reviews on shale inhibitors,the latest advancements in shale chemical inhibitors over the past five years still warrant further discussion and summary.This literature review provided a comprehensive examination of wellbore instability,focusing on the patterns of instability encountered in drilling and the various shale chemical inhibitors employed to mitigate these issues.The review explored the utilization of shale inhibitors in water-based drilling fluids,and the discussion highlights the timeline evolution of these inhibitors,from traditional salts and polymers to advanced ionic liquids and deep eutectic solvents.Additionally,the mechanisms of shale chemical inhibitors are summarized to guide their application.The objective of this paper is to provide a detailed review of the development of shale chemical inhibitors in water-based drilling fluids,aiming to fully appreciate shale hydration inhibition methods and to provide insights into the selection and optimization of shale inhibitors to improve wellbore stability in challengingdrilling environments.
基金supported by State Key Laboratory of Deep Oil and Gas(No.SKLDOG2024-ZYRC-03)supported by the Excellent Young Scientists Fund of the National Natural Science Foundation of China(No.52322401)the National Natural Science Foundation of China(52288101).
文摘As the global exploration and development of oil and gas resources advances into deep formations,the harsh conditions of high temperature and high salinity present significant challenges for drilling fluids.In order to address the technical difficulties associated with the failure of filtrate loss reducers under high-temperature and high-salinity conditions.In this study,a hydrophobic zwitterionic filtrate loss reducer(PDA)was synthesized based on N,N-dimethylacrylamide(DMAA),2-acrylamido-2-methylpropane sulfonic acid(AMPS),diallyl dimethyl ammonium chloride(DMDAAC),styrene(ST)and a specialty vinyl monomer(A1).When the concentration of PDA was 3%,the FLAPI of PDA-WBDF was 9.8 mL and the FLHTHP(180℃,3.5 MPa)was 37.8 mL after aging at 240℃for 16 h.In the saturated NaCl environment,the FLAPI of PDA-SWBDF was 4.0 mL and the FLHTHP(180℃,3.5 MPa)was 32.0 mL after aging at 220℃ for 16 h.Under high-temperature and high-salinity conditions,the combined effect of anti-polyelectrolyte and hydrophobic association allowed PDA to adsorb on the bentonite surface tightly.The sulfonic acid groups of PDA increased the negative electronegativity and the hydration film thickness on bentonite surface,which enhanced the colloidal stability,maintained the flattened lamellar structure of bentonite and formed an appropriate particle size distribution,resulting in the formation of dense mud cakes and reducing the filtration loss effectively.
基金funding support from Guiding Project of Scientific Research Plan of Education Department of Hubei Province and Wuhan Textile University School Fund(B)(k24016).
文摘Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge.Herein,inspired by the human muscle,an anisotropic fire safety aerogel(ACMCA)with precise self-actuated temperature monitoring performance is developed by combining aramid nanofibers with eicosane/MXene to form an anisotropically oriented conductive network.By combining the two synergies of the negative temperaturedependent thermal conductive eicosane,which induces a high-temperature differential,and directionally ordered MXene that establishes a conductive network along the directional freezing direction.The resultant ACMCA exhibited remarkable thermoelectric properties,with S values reaching 46.78μV K^(−1)andκvalues as low as 0.048 W m^(−1)K^(−1)at room temperature.Moreover,the prepared anisotropic aerogel ACMCA exhibited electrical responsiveness to temperature variations,facilitating its application in intelligent temperature monitoring systems.The designed anisotropic aerogel ACMCA could be incorporated into the firefighting clothing as a thermal barrier layer,demonstrating a wide temperature sensing range(50-400℃)and a rapid response time for early high-temperature alerts(~1.43 s).This work provides novel insights into the design and application of temperature-sensitive anisotropic aramid nanofibers aerogel in firefighting clothing.
基金supported by National Natural Science Foundation of China(No.52174013)the Fundamental Research Funds for the Central Universities(24CX02004A)+2 种基金Natural Science Foundation of Shandong Province(ZR2024ME105)The Open Fund for Sinopec's Key Laboratory of Ultra-Deep Well Drilling Engineering and Technology(36650000-23-ZC0607-0063)the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China).
文摘In this study, hydrothermal carbon nanospheres(HCNs) were prepared by hydrothermal carbonization using glucose as the precursor, and introduced to improve the properties of water-based drilling fluid for the first time. The variation in rheological and filtration characteristics of water-based drilling fluid with varying concentrations of HCNs were compared between the cases before and after thermal aging. The results demonstrated that HCNs had little influence on the rheological properties of bentonite base mud,but could effectively reduce its filtration loss after thermal aging at 220℃ For polymer-based drilling fluid, HCNs also exhibited minor influence on the rheology. The H-B model was the best fitting model for the rheological curves before thermal aging. After hot rolling at 220℃,the viscosity retention rate increased from 29% to 63%-90% with addition of HCNs, and the filtration loss decreased by 78% with 1.0w/v% HCNs. Meanwhile, the polymer-based drilling fluid with 0.5 w/v% HCNs maintained relatively stable rheology and low filtration loss after statically thermal aging at 200℃ for 96 h. For a bentonitefree water-based drilling fluid prepared mainly with modified natural polymers, the viscosity retention increased from 21% to 74% after hot rolling at 150℃ with 0.5 w/v% HCNs, and was further improved when HCNs and potassium formate were used in combination. The mechanism study revealed that,HCNs could trap dissolved oxygen, scavenge the free radicals and cross link with polymers, which prevented thermal oxidative degradation of polymers and improved the thermal stability of water-based drilling fluid. Meanwhile, HCNs could inhibit clay hydration and swelling in synergy with partially hydrolyzed polyacrylamide by physically sealing the micropores, contributing to shale formation stability.Furthermore, HCNs could effectively improve the lubrication and anti-wear performance of drilling fluid.This study indicated that HCNs could act as green, sustainable, and versatile additives in water-based drilling fluid.
基金supported by a research grant from the Hoyu Science Foundation in 2023.
文摘This study examined the positive changes that water-based nail treatments can bring to emotions and behavior in children who do not attend school and use a place for school-refusing children.Children who do not attend school and use a place for school-refusing children were given water-based nail treatments about once a week for three months.In addition,the parents of these children were asked to respond to questions about their children’s daily activities.The results showed that natural communication through nail treatments significantly increased positive emotions.However,continued nail treatments did not reduce the children’s problem behaviors.Some children returned to school,while others continued not attending school.Increased frequency of visits and number of treatments confirmed the promotion of communication.It was suggested that building positive relationships with family and supporters is important for achieving sustained effects from nail treatments.This study showed that nail treatments are a useful tool for promoting positive emotions,self-acceptance,and social skills,and may contribute to the emotional growth and social interest of children who do not attend school.
基金This work was supported by the National Natural Science Foundation of China(Nos.61833013,61473012 and 62103335)Key Research Program of Jiangxi Province in China(No.20192BBEL50005).
文摘Forest fires pose a significant threat to human life and property,so the utilization of unmanned aircraft systems provides new ways for forest firefighting.Given the constrained load capacities of these aircraft,aerial refueling becomes crucial to extend their operational time and range.In order to address the complexities of firefighting missions involving multi-receiver and multi-tanker deployed from various airports,first,a fuel consumption calculation model for aerial refueling scheduling is established based on the receiver path.Then,two distinct methods,including an integrated one and a decomposed one,are designed to address the challenges of establishing refueling airspace and allocating tasks for tankers.Both methods aim to optimize total fuel consumption of the receivers and tankers within the aerial refueling scheduling framework.The optimization problem is established as nonlinear optimization models along with restrictions.The integrated method seamlessly combines refueling rendezvous point scheduling and tanker task allocation into unified process.It has a complete solution space and excels in optimizing total fuel consumption.The decomposed method,through the separation of rendezvous point scheduling and task allocation,achieves a reduced computational complexity.However,this comes at the cost of sacrificing optimality by excluding specific feasible solutions.Finally,numerical simulations are carried out to verify the feasibility and effectiveness of the proposed methods.These simulations yield insights crucial for the practical engineering application of both the integrated and decomposed methods in real-world scenarios.This comprehensive approach aims to enhance the efficiency of forest firefighting operations,mitigating the risks posed by forest fires to human life and property.
基金supported by the Preparation and Characterization of Fogging Agents,Cooperative Project of China(Grant No.1900030040)Preparation and Test of Fogging Agents,Cooperative Project of China(Grant No.2200030085)。
文摘Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of the water-based aerosol is always unsatisfactory due to the rapid evaporation and sedimentation of the aerosol droplets.Great efforts have been devoted to improve the stability of water-based aerosol by using additives with different composition and proportion.However,the lack of the criterion and principle for screening the effective additives results in excessive experimental time consumption and cost.And the stabilization time of the aerosol is still only 30 min,which could not meet the requirements of the perdurable interference.Herein,to improve the stability of water-based aerosol and optimize the complex formulation efficiently,a theoretical calculation method based on thermodynamic entropy theory is proposed.All the factors that influence the shielding effect,including polyol,stabilizer,propellant,water and cosolvent,are considered within calculation.An ultra-stable water-based aerosol with long duration over 120 min is obtained with the optimal fogging agent composition,providing enough time for fighting the electro-optic weapon.Theoretical design guideline for choosing the additives with high phase transition temperature and low phase transition enthalpy is also proposed,which greatly improves the total entropy change and reduce the absolute entropy change of the aerosol cooling process,and gives rise to an enhanced stability of the water-based aerosol.The theoretical calculation methodology contributes to an abstemious time and space for sieving the water-based aerosol with desirable performance and stability,and provides the powerful guarantee to the homeland security.
基金supported by the National Natural Science Foundation of China (Grant No.51991361 and Grant No.51874329)。
文摘The environmental hazards and"carbon footprint"of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and animals.This paper explored for the first time the interaction mechanism between natural rubber latex(NRL)and bentonite suspensions(BTs)through a series of characterization experiments,as well as the potential applications in water-based drilling fluids(WBDF).The gel viscoelasticity experiments showed that NRL could decrease the consistency coefficient(k)and flow index(n)of BTs,and enhance the shear thinning performance of BTs as pseudo-plastic fluids.In addition,0.5 w/v%NRL not only increased the critical yield stress and strengthened the structural strength between the bentonite particles,but also facilitated the compatibility of pressure loss and flow efficiency.The evaluation of colloidal stability and WBDF performance indicated that NRL particles could promote the hydration and charge stability on the surface of BTs particles,and optimize the particle size distribution and flow resistance of WBDF under the"intercalation-exfoliation-encapsulation"synergistic interaction.Moreover,NRL can improve the rheological properties of WBDF at high temperatures(<150.C),and form a dense blocking layer by bridging and sealing the pores and cracks of the filter cake,which ultimately reduces the permeability of the cake and the filtration loss of WBDF.
文摘This study tested a chain mediation model on whether hopelessness and nostalgia play a mediating role in psychache and suicidal ideation of firefighters.A total of 652 firefighters participated in the survey(male=94.94%;mean age=23.71 years,SD=4.18 years).The firefighters completed the Chinese Revised Psychache Scale(PAS),Beck Hopelessness Scale(BHS),Southampton Nostalgia Scale(SNS),and Columbia-Suicide Severity Rating Scale(CSSRS).The path analysis results indicated that psychache positively predicted suicidal ideation.Hopelessness plays a significant mediating role between psychache and suicidal ideation further strengthening this relationship.In contrast,nostalgia mediates and weakened the relationship between psychache and suicidal ideation.Hopelessness and nostalgia jointly constructed a chain mediating effect between psychache and suicidal ideation,for higher suicidal ideation with higher hopelessness and lower nostalgia.The findings align with the Three-Step Theory of Suicide,which proposes that suicidal ideation results from the combination of pain and hopelessness and that connectedness is a key protective factor against escalating ideation.Therefore,interventions to reduce suicidal ideation in firefighters should aim to enhance their nostalgia,while reducing sense of hopelessness.
文摘Background:Community-based first responders face high levels of workplace stressors that can pro-foundly impact their physical and mental health.Mindfulness-based interventions have shown promise in decreasing stress and increasing psychological resilience;however,implementation is difficult due to unpredictability of the job,department culture,and generational preferences.The objective of this qualitative study was to identify and enhance understanding of the specific needs and potential barriers and facilitators for the implementation of mindfulness-based programming for community-based first responders.Methods:A phenomenological qualitative study design was used to gain insights into the lived experiences of first responders and elicit perceptions regarding barriers and facilitators for engaging in mindfulness activities.During virtual semi-structured interviews,eleven career firefighters and emergency medical service(EMS)providers offered feedback relative to worksite mindfulness practices,and the use of a stress reduction smartphone application.The Consolidated Framework for Implementation Research was used to guide the analysis relative to barriers and facilitators of implementation success and sustainability.Results:First responders expressed openness to mindfulness-based interventions and a smartphone app that would provide stress reduction content,however,they were adamant that programming needed to be accessible and easily integrated into their workday.They also reinforced that organizational culture and leadership support for their health and well-being were overarching factors essential for implementation success.Conclusions:First responders were supportive of evidence-based mindfulness practices,optimally developed and/or facilitated by someone with intimate knowledge of their unique work environments and challenges.Organizational culture and leadership support were essential for implementation success and sustainability.
基金New Century Excellent Talents in University(NCET-09-0211)Fundamental Research Funds for the Central Universities(2009JBZ015-2)
文摘The wear behaviors of steel-steel pair on condition of a water-based lubricant with copolymer of acylamino polyoxyethylene polyoxypropylene ether(KE-1)included as additives are investigated with the help of the universal micro-tribotester.Tests on friction and wear are carried out.As a reference,some tests with pure water are also performed for comparison.The results show that the prepared water-based lubricant has a good effect on the characteristics associated with friction reducing and anti-wear processes,which lay some credence to its utilization in practical industrial tribo-systems.
基金financially supported by the Natural Science Foundation of China(Grants 51904328)the Natural Science Foundation of China(Grants U1762212)Fundamental Research Funds for the Central Universities(Grants 27R1702031A)
文摘Drilling fluids face failure during drilling deep reservoir with high temperature and high salt.The experimental results show that high temperature and salinity reduce the negative charge on the surface of bentonite in the drilling fluid and cause the coalescence of bentonite particles.As a result,the particles coalesce,the grid structure is destroyed,and the rheological properties,rock-carrying capacity and filtration properties are lost.To resolve the foregoing,in this study,0.05-wt%carbon nanotubes are introduced into a 4%bentonite drilling fluid under conditions where the temperature and concentration of added Na Cl reach 180°C and 10 wt%,respectively.The carbon nanotubes adsorb on the bentonite surface and increase the space among bentonite particles.The steric hindrance prevents the coalescence of bentonite in high temperature and high salt environment.Thus bentonite maintains the small size distribution of bentonite and supports the bentonite grid structure in the drilling fluid.As a result,the rock-carrying capacity of the drilling fluid increases by 85.1%.Moreover,the mud cake formed by the accumulation of small-sized bentonite particles is dense;consequently,the filtration of bentonite drilling fluid reduced by 30.2%.
基金financially supported by the National Natural Science Foundation of China(Grants 51904328)the Natural Science Foundation of China(Grants 52074330)
文摘The demand for non-toxic and biodegradable shale inhibitors is growing in the drilling industry.In this paper,the effect of notoginsenoside(NS)as a new,environmentally friendly inhibitor of shale hydration is systematically studied for the first time.The inhibition performance of NS was evaluated via inhibition evaluation tests,including mud ball immersion tests,linear expansion tests,shale rolling recovery tests,and compressive strength tests.The inhibition mechanism of NS was analyzed using Fourier transform infrared spectroscopy(FTIR),contact angle measurements,particle size distribution determination,thermogravimetric analysis(TGA),and scanning electron microscopy(SEM).The experimental results demonstrate that NS is able to adhere to the clay surface,forming a hydrophobic film that prevents the entry of water molecules and inhibiting the hydration dispersion of the clay.Because of this,NS can maintain the original state of bentonite pellets in water,which can effectively reduce the swelling rate of bentonite,increase the recovery rate of shale drill cuttings,maintain the strength of the shale,and therefore maintain the stability of the borehole wall during drilling.In addition,NS is non-toxic,degradable,and compatible with water-based drilling fluids.The above advantages make NS a promising candidate for use as an environmentally friendly shale inhibitor.
文摘To maintain tight control over rheological properties of high-density water-based drilling fluids, it is essential to understand the factors influencing the theology of water-based drilling fluids. This paper examines temperature effects on the rheological properties of two types of high-density water-based drilling fluids （fresh water-based and brine-based） under high temperature and high pressure （HTHP） with a Fann 50SL rheometer. On the basis of the water-based drilling fluid systems formulated in laboratory, this paper mainly describes the influences of different types and concentration of clay, the content of a colloid stabilizer named GHJ-1 and fluid density on the rheological parameters such as viscosity and shear stress. In addition, the effects of aging temperature and aging time of the drilling fluid on these parameters were also examined. Clay content and proportions for different densities of brine-based fluids were recommended to effectively regulate the rheological properties. Four theological models, the Bingham, power law, Casson and H-B models, were employed to fit the rheological parameters. It turns out that the H-B model was the best one to describe the rheological properties of the high-density drilling fluid under HTHP conditions and power law model produced the worst fit. In addition, a new mathematical model that describes the apparent viscosity as a function of temperature and pressure was established and has been applied on site.
基金funded by the Study on Comprehensive Control of Rocky Desertification and Ecological Service Function Improvement in Karst Peaks(No.2016YFC0502402)Fuling Shale Gas Environmental Exploration Technology of National Science and Technology Special Project(Grant No.2016ZX05060)+2 种基金financially supported by the National Natural Science Foundation of China(No.51709254)Youth Innovation Promotion Association,Chinese Academy of Sciences(No.2020335)Key Research and Development Program of Hubei Province,China(No.2020BCA073)。
文摘Water-based drill cuttings(WBDC)and bauxite are used as raw materials to prepare proppants with low density and high performance.The effects of sintering temperature,sintering period,mixture ratios of materials,doping with iron oxide,and acid modification of WBDC on the properties of proppants are discussed.The proppant performance is evaluated according to the national standard SY/T5108-2014.The morphology of the proppant is analyzed using scanning electron microscopy(SEM).The crystal phase structure of the proppant is studied using X-ray diffraction(XRD).Thermal analysis of the proppant sintering process is performed using thermogravimetry(TG).Proppant Z-23 completely satisfied the SY/T5108-2014 standard.This study provides a new perspective for the resource utilization of water-based drill cuttings and preparation of low-density proppants.
基金support from CNPC Chuanqing Drilling Engineering Company Limited,Chinathe“academic pass”of Southwest Petroleum Universitythe China Postdoctoral Science Foundation(2022M712644)
文摘Considering the increasing environmental pressure,environmentally friendly and high-performance water-based drilling fluids(WBDFs)have been widely studied in recent years to replace the commonly used oil-based drilling fluids(OBDFs).However,few of these drilling fluids are entirely composed of natural materials,which makes it difficult to achieve real environmental protection.Using laponite nanoparticles and various derivatives of natu ral mate rials,including cro sslinked starch,cellulose composite,gelatin ammonium salt,poly-l-arginine,and polyanionic cellulose,a kind of environmentally friendly water-based drilling fluid(EF-WBDF)was built for drilling in environment-sensitive areas.The properties of this EF-WBDF were evaluated by thermal stability tests on rheology,filtration,inhibition,and salt contamination.Besides,biological toxicity,biodegradability,heavy mental content and wheat cultivation tests were conducted to investigate the environmental factor of EF-WBDF.Results showed that EF-WBDF displayed satisfactory thermal resistance up to 150℃,and the rheological properties did not suffer significant fluctuation,showing potential application in high-temperature wells.The optimal rheological model of EF-WBDF was Herschel-Bulkley model.This EF-WBDF performed an eligible filtration of 14.2 mL at 150℃and a differential pressure of 3.5 MPa.This fluid could still maintain colloidal stability after being contaminated by 7.5%NaCl or 0.5%CaC1_(2).Meanwhile,rather low clay swelling degree of 2.44 mm and high shale recovery of more than 95%ensured the inhibitive capability of EF-WBDF.Furthermore,EF-WBDF presented a half maximal effective concentration(EC_(50))of51200 mg/L and a BOD/COD ratio of 47.55%,suggesting that EF-WBDF was non-toxic and easily biodegradable.The wheat cultivated in EF-WBDF could grow healthily,beneficial for reducing the adverse impact on ecological environment.The formed EF-WBDF has a promising future for drilling in environment-sensitive and high-temperature areas.
文摘Underground mine fire always exists since the mining activity was practiced.It poses a severe safety hazard to the mine workers and may also cause a tremendous economic loss to the mines.Methods for controlling and extinguishing fires in underground mine have long been studied and there have been significant improvements.In order to know clearly about the firefighting technology used,this paper summarizes most of the underground mine firefighting methods used in the United States the past 150 years.This paper describes not only the accepted firefighting theories,but also the technologies,both direct and indirect attacking,in accordance to regulations or codes,with special attention is given to the indirect attack method and its related technologies.Further research needed is also briefly discussed at the end of this paper.
基金the National Natural Science Foundation of China(51904329,52174014)the Major Scientific and Technological Projects of CNPC(ZD 2019-183-005)Key R&D Program of Shandong Province(No.2020ZLYS07).
文摘Wellbore instability,especially drilling with water-based drilling fluids(WBDFs)in complex shale for-mations,is a critical challenge for oil and gas development.The purpose of this paper is to study the feasibility of using hydrophobically modified silica nanoparticle(HMN)to enhance the comprehensive performance of WBDFs in the Xinjiang Oilfield,especially the anti-collapse performance.The effect of HMN on the overall performance of WBDFs in the Xinjiang Oilfield,including inhibition,plugging,lu-bricity,rheology,and filtration loss,was studied with a series of experiments.The mechanism of HMN action was studied by analyzing the changes of shale surface structure and chemical groups,wettability,and capillary force.The experimental results showed that HMN could improve the performance of WBDFs in the Xinjiang Oilfeld to inhibit the hydration swelling and dispersion of shale.The plugging and lubrication performance of the WBDFs in the Xinjiang Oilfield were also enhanced with HMN based on the experimental results.HMN had less impact on the rheological and filtration performance of the WBDFs in the Xinjiang Oilfield.In addition,HMN significantly prevented the decrease of shale strength.The potential mechanism of HMN was as follows.The chemical composition and structure of the shale surface were altered due to the adsorption of HMN driven by electrostatic attraction.Changes of the shale surface resulted in significant wettability transition.The capillary force of the shale was converted from a driving force of water into the interior to a resistance.In summary,hydrophobic nanoparticles presented afavorable application potential for WBDFs.
基金financially supported by CNPC Innovation Foundation(2020D-5007-0310)National Natural Science Foundation of China(No.51974354)National Key Research and Development Project(2019YFA0708303)。
文摘Basil seed,containing anionic heteropolysaccharides in its outer pericarp,swells as gelatinous hydrocolloid when soaked in water.In this study,basil seed powder(BSP)was used as a multifunctional additive for water-based drilling fluids.The chemical composition,water absorbency,rheological properties of aqueous suspension of BSP were tested.The effect of BSP on the rheological and filtration of bentonitebased drilling fluid before and after thermal aging was investigated.The inhibition characteristics were evaluated by linear swelling,shale cuttings dispersion and shale immersion test.Lubricity improvement by BSP was measured with extreme pressure lubricity test.The results revealed that incorporation of BSP into bentonite suspension improved rheological and filtration properties effectively after thermal aging of 120℃.BSP exhibited superior inhibitive capacity to xanthan and synergistic effect with KCl.BSP could reduce friction by forming hydration layer.The nanoscale three-dimensional network structures enable BSP to maintain high water retention and absorb strongly on bentonite and metal surface,contributing to enhanced rheology,filtration,inhibition and lubrication properties.The versatile characteristic of BSP,as well as biodegradation makes it a promising additive using in high performance water-based drilling fluid and a potential alternative to conventional synthetic polymers.
