Effect of drilling fluids on coal permeability: Impact on
Data in Table 1 show extensive damage caused by the fluids on the initial coal permeability when drilling overbalanced, which was in the range from 73% to 87% ( Gardes,
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Effect of drilling fluids on coal permeability: Impact on
When coal-derived fines were added to the drilling mud in another experiment using the same coal, the near wellbore coal permeability was reduced by 87.5%, indicating severe
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Effect of drilling fluids on coal permeability: Impact on
The three mud systems tested against coal (Xantham Gum, HEC and Na-CMC) did not have a negative impact on coal permeability, in contrast to previous laboratory data that
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Effect of drilling fluids on coal permeability: Impact on
The objective of this study was to evaluate a series of mud systems and additives typically used in coalbed methane drilling in terms of formation of an instantaneous filter cake, ability of the coal
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Effect of drilling fluids on coal permeability: Impact on
Made available by U.S. Department of Energy Office of Scientific and Technical Information
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The Effect of Drilling Fluid on Coal’s Gas-Water Two-Phase
(1) The addition of anionic surfactants to drilling fluid causes the coal’s hydrophilicity to increase, thereby reducing the permeability of the CBM reservoir and affecting its production
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Effect of drilling fluids on coal permeability: Impact on
The objective of this study was to evaluate a series of mud systems and additives typically used in coalbed methane drilling in terms of formation of an instantaneous filter cake, ability of the coal
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Research on the effect of drilling fluid’s pH value on the
The influence law of drilling fluid’s pH value on the coal’s wettability was studied through lots of experiments, the results showed that the wettability was related to the pH value
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Effects of coal damage on permeability and gas drainage
However, it should be noted that previous scholars mainly focus on the influence of coal mechanical properties and gas sorption/adsorption on permeability variation, and the
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Impact of Drilling Fluid Contamination on Performance of
The thickening time may be reduced, which leads to the setting of cement at unpredicted depth and causes well integrity issues. Abdel-Alim and El-Sayed (1995) showed
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Effect of drilling fluids on coal permeability: Impact on
Fluid invasion during drilling and completion operations can produce formation damage and promote lost circulation of mud and cement. The flow of drilling mud filtrate and solute (dissolved ions and molecules) into a low-permeability and highly-microfractured coal seam can have a profound effect on near-wellbore pressures, stress,
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The Effect of Drilling Fluid on Coal s Gas-Water Two
The stress sensitivity of high-gas and low-permeability coal seams directly impinges on the effectiveness of pressure relief mining [13, 14]. Permeability changescan bevery large during the depletion of coal bed methane wells. The increase in the absolute permeability of coal beds is a result of matrix
Get PriceThe Effect of Drilling Fluid on Coal’s Gas-Water Two
In the process of coal bed methane (CBM) production, the output of CBM is mainly related to the relative permeability of gas and water in coal seams. However, during the drilling process, the invasion of drilling fluid into CBM reservoirs changes the wettability, which may cause the gas and water’s redistribution through the pores and cracks, further changing
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The effects of drilling fluids and environment protection
The jets of drilling fluid lift the cuttings from the bottom of the hole and away from the bit so the cuttings do not interfere with the effectiveness of the drill bit. The drilling fluid circulates and rises to the surface through the annulus between the drill string and the casing (HWU 2009 ). Cooling and lubricating
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Combined control of fluid adsorption capacity and initial
The variations of strain and permeability of coal were systematically studied through the physical simulation of N2 and water injection. The effects of fluid adsorption capacity and initial permeability on strain, permeability and the dominant effect of pore pressure were discussed. The adsorption strain and strain rate of coal during water
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Effect of <i>in-situ</i> stress on the cracking and
With the gradual development of coal mining to deeper levels, the in-situ stress of coal seams shows an increasing trend, resulting in a gradual decrease in permeability, and the stress state of the coal and rock mass and the properties of the surrounding rock also change. The mechanical properties and mechanical parameters of coal and rock
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Effect of lignin source and initiation conditions on graft
To control the fluid loss in the drilling fluid, the design should be done in such a way that a thin filter cake with low permeability is created on the wall of the drilling well to prevent the separation of the water phase from fluid and penetration into the pores of the well wall (Davoodi et al., 2019). Due to larger size and also more
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国外微泡沫钻井液技术新进展及探讨
Based on the problems presented above, the research direction of micro foam drilling fluid technology is discussed from three aspects, which are:the percolation flow pattern of micro foams in porous media and its affecting factors, chemical additives for micro foam drilling fluids, and the formulation method of micro foam drilling fluids.
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Comparison between the observed coal permeability
Download scientific diagram Comparison between the observed coal permeability change in the lab and the theoretical solution, both of which are bounded by free swelling and constant volumetric
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Experimental Study on Mechanics and Permeability
In this paper, we investigated the mechanical and permeability characteristics of water-bearing raw coal samples under in-situ stress, and came to some conclusions, as follows: the peak strength and peak axial strain of samples gradually decrease with the increase of water content. Under the same stress condition, the higher the water content
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Effect of drilling fluids on coal permeability: Impact on
Article “Effect of drilling fluids on coal permeability: Impact on horizontal wellbore stability” Detailed information of the J-GLOBAL is a service based on the concept of Linking, Expanding, and Sparking, linking science and technology information which hitherto stood
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Experimental investigation of the cementation and tensile
In the stage of well drilling, the formation is exposed to drilling fluid. Then spacers and chemical washes are pumped ahead of the cement slurry for fluid separation and hole cleaning. Ideally, the drilling process leaves a formation surface to which the cement can bond and provide zonal isolation (Ladva et al. 2005 ).
Get PriceEffect of lignin source and initiation conditions on graft
To control the fluid loss in the drilling fluid, the design should be done in such a way that a thin filter cake with low permeability is created on the wall of the drilling well to prevent the separation of the water phase from fluid and penetration into the pores of the well wall (Davoodi et al., 2019). Due to larger size and also more
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Combined control of fluid adsorption capacity and initial
The variations of strain and permeability of coal were systematically studied through the physical simulation of N2 and water injection. The effects of fluid adsorption capacity and initial permeability on strain, permeability and the dominant effect of pore pressure were discussed. The adsorption strain and strain rate of coal during water injection are significantly
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Effect of <i>in-situ</i> stress on the cracking and
With the gradual development of coal mining to deeper levels, the in-situ stress of coal seams shows an increasing trend, resulting in a gradual decrease in permeability, and the stress state of the coal and rock mass and the properties of the surrounding rock also change. The mechanical properties and mechanical parameters of coal and rock mass greatly differ
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Drilling Fluids: Tackling Drilling, Production, Wellbore
Drilling Fluids: Tackling Drilling, Production, Wellbore Stability, and Formation Evaluation Issues in Unconventional Resource Development Mapping Intimacies 10.1190/urtec2013-105
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Experimental Study on Damage Fracture Law of Coal from
after a solid propellant is excited, the high-temperature and high-pressure gas is produced in the hole and rapidly expands and impacts the hole wall, thus forming a large range of crack zone around the blast hole, which improves the crack development level of the coal reservoir to a certain extent, dredges the seepage channel, and improves the
Get PriceProcesses Free Full-Text Effects of Hydration during
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 during drilling. The results of a rock triaxial mechanical test conducted to evaluate the mechanical properties of shale oil reservoirs are
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Experimental Study on Mechanics and Permeability
The permeability of coal samples increases volatility with the increase of axial strain, and the fitted sample permeability and effective stress are subject to the ExpDec1 function distribution. Keywords: water content; in-situ stress; post-peak loading and unloading; mechanical properties; permeability characteristics 1. Introduction
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Drilling fluid AAPG Wiki
Purpose of fluids. An essential element of drilling a well is the drilling fluid or mud. Drilling fluids serve a number of functions: Removal of cuttings from the bottom of the hole. Suspend cuttings and weight material. Transport cuttings and gas to the surface. Cool and lubricate the bit and drill string. Add bouyancy to the drill string.
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