In the process of the exploration and development of shale oil, the influence of hydration on shale reservoirs is complex, as it can not only improve porosity and permeability, but also lead to reservoir instability. At present, there is a lack of sy...
Shale inhibitor is an additive for drilling fluids that can be used to inhibit shale hydration expansion and dispersion, and prevent wellbore collapse. Small molecular quaternary ammonium salt can enter the interlayer of clay crystal, and enables an...
The characteristics of laminae in lamellar shale oil reservoirs have important influences on reservoir parameters, especially permeability. In order to explore the influence of lamina density and occurrence on the permeability of lamellar shale after...
Water uptake induced by fluid–rock interaction plays a significant role in the recovery of flowback water during hydraulic fracturing. However, the existing accounts fail to fully acknowledge the significance of shale anisotropy on water uptake...
Based on the adsorption mechanism analysis of polyhydroxy organic compound on a shale surface, a novel polyhydroxy organic amine shale hydration inhibitor N, N, N′, N′-tetrakis (2-hydroxyethyl) ethylenediamine (THEED) was synthesized via...
The interaction between drilling fluid and shale has a significant impact on wellbore stability during shale oil and gas drilling operations. This paper investigates the effects of the drilling fluid activity on the surface and osmotic hydration char...
It is well known that the effect of shale hydration causes wellbore instability due to water phase invasion of drilling fluid to lamellar shale rich formations. This is because of that the mechanical properties (compressive strength, elastic modulus,...
Acoustic-wave velocities of shale rocks with different coring angles were tested by an acoustic-emission experiment under different confining pressures and soaking time of drilling fluid. Effects of stress and hydration coupling on the acoustic-wave...
Accurate evaluation of shale oil reservoir fracability helps avoid blind fracturing and ensures efficient fracturing. However, the current evaluation of the fracability index rarely considers the impact of hydration caused by drilling fluid invasion...
Shale oil is an unconventional kind of oil and gas resource with great potential. China has huge reserves of shale oil, and shale oil resources are abundant in the third submember of the Triassic Chang 7 member in the southern Ordos Basin. At present...
Shale reservoirs contain a certain amount of clay minerals, which can hydrate through imbibition when in contact with various water-based fluids during drilling and completion. Shale hydration can lead to structural changes in the shale such as the e...
In the process of the exploitation of deep oil and gas resources, shale wellbore stability control faces great challenges under complex temperature and pressure conditions. It is difficult to reflect the micro mechanism and process of the action of i...
Wellbore instability caused by the hydration of shale formations during drilling is a major problem in drilling engineering. In this paper, the shale inhibition performance of polyhydroxy-alkanolamine was evaluated using an anti-swelling test, linear...
Drilling fluids play an essential role in shale gas development. It is not possible to scale up the use of water-based drilling fluid in shale gas drilling in Yunnan, China, because conventional inhibitors cannot effectively inhibit the hydration of...
The stress threshold of deep reservoir shale subjected to fracturing fluid immersion is an important factor affecting fracture initiation and propagation during fracturing. However, little information has been reported on the effect on shale of soaki...
Shale hydration dispersion and swelling are primary causes of wellbore instability in oil and gas reservoir exploration. In this study, inulin, a fructo-oligosaccharide extracted from Jerusalem artichoke roots, was modified by acylation with three ac...
Oil shale, as a vast potential resource, is considered an important alternative energy source, and its effective development and economic utilization are of significant importance in alleviating the contradiction between energy supply and demand. Pre...
In the process of hydraulic fracturing, fracturing fluid invades the formation and reacts with shale. Water-sensitive clay minerals swell when exposed to water. This results in a change in the mechanical properties of shale. However, the influences o...
The Chang 7 member of the Ordos Basin hosts abundant shale oil and gas resources and plays a vital role in the development of unconventional energy. This study investigates differences in damage evolution and underlying mechanisms between representat...
In this study, a new polyionic polymer inhibitor, TIL-NH2, was developed to address the instability of shale gas horizontal wells caused by water-based drilling fluids. The structural characteristics and inhibition effects of TIL-NH2 on mud shale wer...
Clay minerals are an important part of the mud shale reservoir, and their type of content has a great impact on the hydration of the formation. The hydration of clay minerals causes a decrease in drilling fluid performance, an increase in pore pressu...
Research on using nanotechnology to solve shale instability problems in drilling engineering has been increasing. The combination of amphiphilic polymer and silica nanoparticles may be a new way to improve shale stability. Herein, an amphiphilic poly...
Designing an effective drilling mud is a critical aspect of the drilling process. A well-designed drilling mud should not only provide efficient mud hydraulics but also fulfill three important functions: enhancing mud rheology, inhibiting hydrate for...
To investigate the mechanism by which the rheological properties of drilling fluids affect the stability of the wellbore in brittle mud shale, this study systematically examines the influence of drilling fluids with different rheological properties o...
The drilling of clay-rich formations, such as shale, is an extremely demanding technical and technological process. Shale consists of mixed clay minerals in different ratios and in contact with water from drilling mud. It tends to swell and cause dif...
The shale oil horizontal wells in the Songliao Basin are affected by a lack of mature theories, technologies and experiences in the direction of wellbore stability. Wellbore collapse may occur, and in severe cases, the wellbore may be scrapped, resul...
In this paper, small-molecule quaternary ammonium salts were synthesized by N-alkylation to inhibit hydration swelling and hydration dispersion. The prepared small-molecule quaternary ammonium salt was characterized by Fourier transform infrared (FTI...
In this work, a novel low molecular weight zwitterionic copolymer for improving wellbore stability, which is expected to be an alternative to the current shale inhibitors, was obtained by copolymerization of tris hydroxyethyl allyl ammonium bromide (...
In this study, lightweight ultra-high-performance concrete (L-UHPC) was prepared by using SP to replace part of the cement. The main study investigated the effect of the amount of SP on the spread diameter, apparent density and mechanical properties...
The issue of wellbore instability poses a significant challenge in the current exploration of shale gas reservoirs. Exploring more efficient shale stabilizers has always been a common goal pursued by researchers. In this paper, a novel shale stabiliz...
Moisture significantly affects the mechanical behavior of gas shale and further determines the hydraulic fracturing performance, as it is more attractive. Nevertheless, batch experiments have usually involved variable methodologies regarding the prep...
The global shale gas resources are huge and have good development prospects, but shale is mainly composed of nanoscale pores, which have the characteristics of low porosity and low permeability. Horizontal drilling and volume fracturing techniques ha...
Shale inhibition, low-temperature performance, the ability to prevent calcium and magnesium-ion pollution, and hydrate inhibition of polyethylene glycol drilling fluid were each tested with conventional drilling-fluid test equipment and an experiment...
The characteristics of marine–continental transitional shale reservoirs and the performance parameters of fracturing fluids, such as pH and mineralization, play a crucial role in influencing the flowback efficiency of these fluids. Excessive re...
It is widely accepted in the oil and gas industry that high-ionic-strength water (HISW) can improve oil and gas recovery in unconventional shale reservoirs by limiting shale hydration. Despite numerous supporting studies, there is a lack of a systema...
An inhibitor that can effectively inhibit shale hydration is necessary for the safe and efficient development of shale gas. In this study, a novel ionic liquid copolymer shale inhibitor (PIL) was prepared by polymerizing the ionic liquid monomers 1-v...
With the application of CO2 fracturing, CO2 huff and puff, CO2 flooding, and other stimulation technologies in shale reservoirs, a large amount of CO2 remained in the formation, which also lead to the serious corrosion problem of CO2 in shale reservo...
The Gulong shale oil reservoir is situated in freshwater to slightly saline lacustrine basins mainly consisting of a pure shale geological structure, which is quite different from other shale reservoirs around the world. Currently, the development of...
Economic and technological factors necessitate the use of alternative fuels during oil shale combustion, a process that generates substantial amounts of solid waste with varying ash compositions. This study evaluates the potential of two such waste m...
The shale of the lower Cambrian Niutitang formation in northwestern Hunan is an ideal reservoir for shale gas. There is a close connection between borehole stability and drilling fluid in shale gas drilling. Ionic stabilizer is a new type of stratum...
Black shale, which usually contains pyrite, is easily oxidized and generates acid discharge. This acidic environment is not favorable for concrete in engineering applications and is likely to affect the durability of engineering structures. This stud...
Hydraulic fracturing technology significantly enhances the productivity of shale oil and gas reservoirs. Nonetheless, the infiltration of fracturing fluid into shale formations can detrimentally affect the microscopic pore structure, thereby impairin...
During the oil shale drilling in Group Q of Block GL, the shale is prone to hydration, deterioration, sidewall exfoliation and frequent collapse, which affects the efficient exploration and development of shale oil. In order to reveal the mechanism o...
Mitigation of greenhouse gas emissions is becoming a significant factor in all industries. Cement manufacturing is one of the industries responsible for greenhouse gas emissions, specifically carbon dioxide emissions. Pozzolanic materials have long b...
During the process of oil and gas drilling, due to the existence of pores or micro-cracks, drilling fluid is prone to invade the formation. Under the action of hydration expansion of clay in the formation and liquid pressure, wellbore instability occ...
One of the foremost causes of wellbore instability during drilling operations is shale swelling and hydration induced by the interaction of clay with water-based mud (WBM). Recently, the use of surfactants has received great interest for preventing s...
Hydraulic fracturing is widely used for developing shale reservoirs with low porosity and permeability. Large volumes of fracturing fluids are injected into reservoirs, yet the impact of these fluids on shale is not entirely understood. This study in...
Our research group prepared a new filling paste consisting of steel slag–oil shale residue and no admixtures. It was used as the research object to explore the combined effect of chloride and dry–wet cycling-driven erosion on the long-ter...
Water imbibition is a key factor affecting the flowback regime of shale gas wells after volume fracturing. In this study, a set of experimental apparatus and corresponding test and evaluation methods were developed to analyze the laws of forcible imb...
The decomposition of hydrates can cause serious sand production and collapse problems, hindering the long-term effective production of hydrates. This study proposes a theory for framework reconstruction and reinforcement for deep-water hydrate layers...
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