Study on the stability and green application exploration of waste drilling fluid

A dual gradient, deepwater drilling system based on dilution of riser mud requires economically separating the riser mud into a low density dilution fluid and a higher density drilling fluid. This study investigated the practicality of accomplishing this separation using hydrocyclones and centrifuges and examined the possible benefits and efficiency of each. The separation experiments were conducted using a laboratory centrifuge and 2 inch hydrocyclones. The laboratory centrifuge was able to separate the riser mud into near ideal densities for dilution and drilling fluid. However, the dense slurry retained in the centrifuge had lower emulsion stability than the feed stream. The hydrocyclones achieved much less contrast in density between the low and high density discharges, but consistently resulted in a beneficial increase in the stability of the mud emulsion in all of the flow streams and had more desirable rheological properties. A qualitative comparison indicates that the hydrocyclone separation system may offer a feasible and desirable alternative to centrifuge separation system.

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Nanoemulsion with Controlled Rheology under Different Temperature for Effective Removal of Oil-based Drilling Fluid in Offshore Drilling

10.1115/omae2021-62851 ◽

2021 ◽

Author(s):

Renzhou Meng ◽

Chengwen Wang ◽

Xiliang Dong ◽

Chao Xiong

Keyword(s):

High Temperature ◽

Low Temperature ◽

Rheological Properties ◽

Drilling Fluid ◽

Offshore Drilling ◽

Emulsion Droplets ◽

Effective Removal ◽

Engineering Requirement ◽

Important Means ◽

The Stability

Abstract Oil-based drilling fluid (OBDF) is an important means for offshore drilling, but it would affect the cementing quality. Nanoemulsions shows potential for OBDF removal, but how to prepare nanoemulsion meeting the engineering requirement is lack of good understanding. Moreover, nanoemulsions usually behave badly under low/high temperature, which would restrict the application. Revealing removal mechanisms of nanoemulsion and improving nanoemulsion stability at different temperature are of great significance. The nanoemulsion could rapidly spread on the wellbore surfaces, cause the adhering OBDF to curl into little droplets, and solubilize the removed OBDF. The removal efficiency can reach more than 98%. Low temperature and higher concentration of dispersed phase both increased the viscosity of nanoemulsions stabilized by surfactants. PEGs can induce the bridging of emulsion droplets at low temperature, leading to significant increase of nanoemulsions viscoelasticity at low temperature (around 5°C). To control the rheological properties of nanoemulsions, a hydrophobic association polymer, HAAP, was proposed. Nanoemulsions containing HAAP does not gel at low temperature (< 15°C). And the viscoelasticity of nanoemulsions increased slightly when the temperature is higher than 70°C because of the thermoassociating behavior of polymer, which can ensure the stability of the nanoemulsions at high temperature. This paper is helpful to establish a generic route for preparing nanoemulsions with controlled rheological properties under different temperature, which is benefit for their applications in offshore.

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Experimental Investigation of Water Based Colloidal Gas Aphron Fluid Stability

Colloids and Interfaces ◽

10.3390/colloids3010031 ◽

2019 ◽

Vol 3 (1) ◽

pp. 31 ◽

Cited By ~ 2

Author(s):

Seyed Hosseini-Kaldozakh ◽

Ehsan Khamehchi ◽

Bahram Dabir ◽

Ali Alizadeh ◽

Zohreh Mansoori

Keyword(s):

Xanthan Gum ◽

Drilling Fluid ◽

Sodium Dodecyl ◽

Ammonium Bromide ◽

Drilling Fluids ◽

Size Distributions ◽

Electrolyte System ◽

Colloidal Gas Aphron ◽

The Stability ◽

Filtration Properties

Today, the drilling operators use the Colloidal Gas Aphron (CGA) fluids as a part of drilling fluids in their operations to reduce formation damages in low-pressure, mature or depleted reservoirs. In this paper, a Taguchi design of experiment (DOE) has been designed to analyse the effect of salinity, polymer and surfactant types and concentration on the stability of CGA fluids. Poly Anionic Cellulose (PacR) and Xanthan Gum (XG) polymers are employed as viscosifier; Hexadecyl Trimethyl Ammonium Bromide (HTAB) and Sodium Dodecyl Benzene Sulphonate (SDBS) have been also utilized as aphronizer. Moreover, bubble size distributions, rheological and filtration properties of aphronized fluids are investigated. According to the results, the polymer type has the highest effect, whereas the surfactant type has the lowest effect on the stability of CGA drilling fluid. It was also observed that increasing salinity in CGA fluid reduces the stability. Finally, it should be noted that the micro-bubbles generated with HTAB surfactant in an electrolyte system, are more stable than SDBS surfactant.

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Study on the stability of a shear-thinning suspension used in oil well drilling

Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles ◽

10.2516/ogst/2018007 ◽

2018 ◽

Vol 73 ◽

pp. 10 ◽

Cited By ~ 7

Author(s):

Flávia M. Fagundes ◽

Nara B.C. Santos ◽

João Jorge R. Damasceno ◽

Fábio O. Arouca

Keyword(s):

Gamma Ray ◽

Drilling Fluid ◽

Shear Thinning ◽

Drilling Fluids ◽

Oil Well ◽

Drilling Process ◽

Well Drilling ◽

Constant Rate ◽

The Stability ◽

Solid Liquid

In order to avoid solid-liquid gravitational separation of particles in the drilling fluid and cuttings generated in this process, the oil industry has been developing drilling fluids with shear-thinning and thixotropic characteristics. In case of operational stops in the drilling process, the intense sedimentation of these particles can damage the equipment used and the well. In this context, this study simulated an operational stop to obtain information about stability of solids in a paraffin-based suspension with time-dependent shear-thinning behavior, which has already been used in current drilling processes. A long-term test using gamma-ray attenuation technique identified the separation dynamics of a set of micrometric particles belonging to and incorporated into the drilling fluid during operation. This test verified the typical regions of gravitational sedimentation and, through constant concentration curves, indicated that the sedimentation process did not occur at a constant rate. This study also proposed a constitutive equation for pressure on solids.

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Evaluation of Constitutive Equation for Stress in Solids in Porous Media Composed of Bridging Agents Used in Drilling Fluids

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1878 ◽

2012 ◽

Vol 727-728 ◽

pp. 1878-1883 ◽

Cited By ~ 2

Author(s):

Bruno Arantes Moreira ◽

Flávia Cristina Assis Silva ◽

Larissa dos Santos Sousa ◽

Fábio de Oliveira Arouca ◽

João Jorge Ribeiro Damasceno

Keyword(s):

Porous Media ◽

Constitutive Equation ◽

Filter Cake ◽

Drilling Fluid ◽

Fluid Loss ◽

Drilling Fluids ◽

Oil Well ◽

Well Drilling ◽

Drilling Operations ◽

The Stability

During oil well drilling processes in reservoir-rocks, the drilling fluid invades the formation, forming a layer of particles called filter cake. The formation of a thin filter cake and low permeability helps to control the drilling operation, ensuring the stability of the well and reducing the fluid loss of the liquid phase in the interior of the rocks. The empirical determination of the constitutive equation for the stress in solids is essential to evaluate the filtration and filter cake formation in drilling operations, enabling the operation simulation. In this context, this study aims to evaluate the relationship between the porosity and stress in solids of porous media composed of bridging agents used in drilling fluids. The concentration distribution in sediments was determined using a non-destructive technique based on the measure of attenuated gamma rays. The procedure employed in this study avoids the use of compression-permeability cell for the sediment characterization.

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Some issues of ensuring the stability of the walls of directional wells and preventing the absorption of process fluids

Proceedings of OilGasScientificResearchProjects Institute SOCAR ◽

10.5510/ogp2021si100510 ◽

2021 ◽

pp. 60-67

Author(s):

A.N. Popov ◽

◽

R.A. Ismakov ◽

A.R. Yakhin ◽

I.D. Mukhametgaliev ◽

...

Keyword(s):

Hydraulic Fracturing ◽

Drilling Fluid ◽

Fluid Pressure ◽

Polycrystalline Diamond ◽

Horizontal Wells ◽

Rotary Drilling ◽

The Stability ◽

Diamond Bit ◽

Hydrodynamic Effects ◽

The Given

Most of the main types of complications in the process of drilling wells, such as collapses, taluses, collapses of the walls, the formation of caverns, etc., are associated with external mechanical and hydrodynamic effects on the walls of the wellbore. Therefore, ensuring the stability of the borehole walls is one of the urgent and difficult technological formation fluid pressure on mechanical processes in rocks when they are opened with a directional well, especially of horizontal wells. This article provides solutions to problems associated with hydraulic fracturing of a well and the condition of its prevention, calculation of generalized stresses in the rock formation for inclined well. As a result of this calculations, the necessary data are obtained for making a decision on the density of the drilling fluid to drilling the considered interval of rocks, as well as for making other technological decisions. The given calculation formulas make it possible to fully evaluate the effect of the formation fluid pressure on the mechanical processes in the rocks when they are opened by a horizontal well. Keywords: hydraulic fracturing; blade bit; steel ball-shaped toothed bit; polycrystalline diamond bit; laser drilling; impact rope drilling; rotary drilling.

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On the Stability of Oil-Based Drilling Fluid: Effect of Oil-Water Ratio

Volume 11: Petroleum Technology ◽

10.1115/omae2020-19071 ◽

2020 ◽

Author(s):

Titus Ntow Ofei ◽

Itung Cheng ◽

Bjørnar Lund ◽

Arild Saasen ◽

Sigbjørn Sangesland

Keyword(s):

North Sea ◽

Storage Stability ◽

Drilling Fluid ◽

Stability Index ◽

Drilling Fluids ◽

Flow Transition ◽

Water Based ◽

Oil Water ◽

The Stability ◽

Transition Index

Abstract Drilling fluids are complex mixtures of natural and synthetic chemical compounds used to cool and lubricate the drill bit, clean the wellbore, carry drilled cuttings to the surface, control formation pressure, and improve the function of the drill string and tools in the hole. The two main types of drilling fluids are water-based and oil-based drilling fluids, where the oil-based also include synthetic-based drilling fluids. Many rheological properties of drilling fluids are key parameters that must be controlled during design and operations. The base fluid properties are constructed by the interaction of the emulsified water droplets in combination with organophilic clay particles. The rheological properties resulted from this combination, along with the particle size distribution of weight materials are vital in controlling the physical stability of the microstructure in the drilling fluid. A weak fluid microstructure induces settling and sagging of weight material particles. The presence of sag has relatively often been the cause for gas kicks and oil-based drilling fluids are known to be more vulnerable for sag than water-based drilling fluids. Hence, the shear-dependent viscosity and elasticity of drilling fluids are central properties for the engineers to control the stability of weight material particles in suspension. In this study, we examined the stability of typical oil-based drilling fluids made for North Sea oilfield drilling application with oil-water-ratios (OWR) of 80/20 and 60/40. The structural character of the fluid samples was analyzed both at rest and dynamic conditions via flow and viscosity curves, amplitude sweep, frequency sweep, and time-dependent oscillatory sweep tests using a rheometer with a measuring system applying a grooved bob at atmospheric conditions. A high precision density meter was used to measure the density of the drilling fluid samples before and after each test. The measurement criteria used to rank the fluids stability include the yield stress as measured from flow curves and oscillatory tests, flow transition index, mechanical storage stability index, and dynamic sag index. We observed that between the two drilling fluids, the sample with OWR = 60/40 showed a stable dispersion with stronger network structure as evidenced by higher yield stress and flow transition index values, while the mechanical storage stability index and dynamic sag index recorded lower values. The results of this study enable drilling fluid engineers to design realistic oil-based drilling fluids with stable microstructure to mitigate settling and sagging of weight material particles for North Sea drilling operation.

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Coupled THM Modelling of Wellbore Stability with Drilling Unloading, Fluid Flow, and Thermal Effects Considered

Mathematical Problems in Engineering ◽

10.1155/2019/5481098 ◽

2019 ◽

Vol 2019 ◽

pp. 1-20

Author(s):

Shanpo Jia ◽

Caoxuan Wen ◽

Fucheng Deng ◽

Chuanliang Yan ◽

Zhiqiang Xiao

Keyword(s):

Fluid Flow ◽

Pore Pressure ◽

Thermal Effects ◽

Process Analysis ◽

Drilling Fluid ◽

Wellbore Stability ◽

Deep Well ◽

Underbalanced Drilling ◽

The Stability ◽

Pressure Stress

Both overbalanced drilling and underbalanced drilling will lead to the change of pore pressure around wellbore. Existing research is generally based on hydraulic-mechanical (HM) coupling and assumes that pore pressure near the wellbore is initial formation pressure, which has great limitations. According to the coupled theory of mixtures for rock medium, a coupled thermal-hydraulic-mechanical (THM) model is proposed and derived, which is coded with MATLAB language and ABAQUS software as the solver. Then the wellbore stability is simulated with the proposed model by considering the drilling unloading, fluid flow, and thermal effects between the borehole and the formation. The effect of field coupling on pore pressure, stress redistribution, and temperature around a wellbore has been analyzed in detail. Through the study of wellbore stability in different conditions, it is found that (1) for overbalanced drilling, borehole with impermeable wall is more stable than that of ones with permeable wall and its stability can be improved by reducing the permeable ability of the wellbore wall; (2) for underbalanced drilling, the stability condition of permeable wellbore is much higher than that of impermeable wellbore; (3) the temperature has important influence on wellbore stability due to the variation of pore pressure and thermal stress; the wellbore stability can be improved with cooling drilling fluid for deep well. The present method can provide references for coupled thermal-hydraulic-mechanical-chemical (THMC) process analysis for wellbore.

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Enhancing the Stability of Invert Emulsion Drilling Fluid for Drilling in High-Pressure High-Temperature Conditions

Energies ◽

10.3390/en11092393 ◽

2018 ◽

Vol 11 (9) ◽

pp. 2393 ◽

Cited By ~ 11

Author(s):

Salaheldin Elkatatny

Keyword(s):

High Pressure ◽

High Temperature ◽

Rheological Properties ◽

Drilling Fluid ◽

Electrical Stability ◽

Dynamic Conditions ◽

High Pressure High Temperature ◽

Invert Emulsion ◽

The Stability ◽

Filtration Properties

Drilling in high-pressure high-temperature (HPHT) conditions is a challenging task. The drilling fluid should be designed to provide high density and stable rheological properties. Barite is the most common weighting material used to adjust the required fluid density. Barite settling, or sag, is a common issue in drilling HPHT wells. Barite sagging may cause many problems such as density variations, well-control problems, stuck pipe, downhole drilling fluid losses, or induced wellbore instability. This study assesses the effect of using a new copolymer (based on styrene and acrylic monomers) on the rheological properties and the stability of an invert emulsion drilling fluid, which can be used to drill HPHT wells. The main goal is to prevent the barite sagging issue, which is common in drilling HPHT wells. A sag test was performed under static (vertical and 45° incline) and dynamic conditions in order to evaluate the copolymer’s ability to enhance the suspension properties of the drilling fluid. In addition, the effect of this copolymer on the filtration properties was performed. The obtained results showed that adding the new copolymer with 1 lb/bbl concentration has no effect on the density and electrical stability. The sag issue was eliminated by adding 1 lb/bbl of the copolymer to the invert emulsion drilling fluid at a temperature >300 °F under static and dynamic conditions. Adding the copolymer enhanced the storage modulus by 290% and the gel strength by 50%, which demonstrated the power of the new copolymer to prevent the settling of the barite particles at a higher temperature. The 1 lb/bbl copolymer’s concentration reduced the filter cake thickness by 40% at 400 °F, which indicates the prevention of barite settling at high temperature.

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Bentonite Suspension Filtration and its Electro-Kinetics in the Presence of Additives

Tenside Surfactants Detergents ◽

10.1515/tsd-2020-2257 ◽

2021 ◽

Vol 58 (2) ◽

pp. 121-126

Author(s):

R. M. Farag ◽

A. M. Salem ◽

A. A. El-Midany ◽

S. E. El-Mofty

Keyword(s):

Zeta Potential ◽

Rheological Properties ◽

Electrostatic Interactions ◽

Drilling Fluid ◽

Colloidal Suspensions ◽

Drilling Fluids ◽

Fluid Filtration ◽

Filtration Loss ◽

Suspension Filtration ◽

The Stability

Abstract Invasion of fluids into porous media during drilling can lead to irreparable damage and reduced well productivity. Hence, minimizing the filtration loss of the drilling fluid into the formation is very important. The stability of colloidal suspensions plays a crucial role in controlling the interfacial forces and consequently on minimizing the filtration. The zeta potential is an indicator of the stability of colloids with respect to their electrostatic interactions. In this study, the rheological properties of bentonite suspensions are investigated with and without additives. The starch and CMC were used as additives to enhance the rheological properties of bentonite. The effects of these additives on the drilling fluid filtration were examined. Zeta-potential, viscosity, gel strength and yield point were measured to characterize the extent to which control of the filtration loss of the drilling fluids can be achieved. The zeta-potential and the amount of filtration loss of water-bentonite suspensions were correlated. Finally, the results showed that the addition of either starch or carboxymethyl cellulose (CMC) enhances the filtration properties of water-bentonite suspensions.

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