Drilling Mud Research Articles

Sterilized Chicken Feather as Eco-friendly Corrosion Inhibitor for Mild Steel in a Water- Based Drilling Mud – Gravimetric and FTIR Assessment

This research evaluated the corrosion performance of mild steel in sterilized and unsterilized alkaline mud corroding systems using chicken feather powder (CFP) obtained through the usual hydrolysis and acid neutralization protocol. Insightfully, gravimetric analysis revealed that bacterial infestation of the unsterilized environment caused its corrosion performance to be lower at 10.3% while the sterilized counterpart stood at 49% at 92 days of exposure to the environments respectively. The functional groups, C=N, O=C=O, H-C=O etc, revealed by FTIR to be present in the protein saturated feather were overwhelmed by microbial activities rendering them inactive to perform as inhibitors.

Effect of temperature on transport index of fish oil-based drilling mud in high pressure high temperature well: a hybrid model approach

Diesel Oil-based drilling mud used in the oil and gas industry causes severe environmental and public health issues due to its high toxicity, especially in high-pressure, high-temperature (HPHT) wells. Therefore, easily biodegradable synthetic oil-based mud with high drilling performance is essential. Fish oil is a bio-oil known for its non-toxicity, high lubricity, thermal stability, and biodegradability. Effective hole cleaning is crucial for drilling performance and is ensured by the rheological properties of drilling mud. While rheological parameter prediction can be performed using an artificial neural network (ANN) based model, such models often fail to provide accurate predictions for unseen data. In contrast, empirical models are more robust and facilitate generalization. This study aims at assessment of the suitability of invert emulsion fish oil-based drilling mud (IEFOBDM) in HPHT wells through evaluation of hole cleaning performance (HCP) using a hybrid approach that combines an ANN with nonlinear regression (NLR) for temperatures ranging from 40 °C to 80 °C.Firstly, an ANN model was developed considering mud weight, temperature, and shear rate. Secondly, the NLR model was used in the prediction of rheological parameters, namely, Yield point (YP) and Plastic viscosity (PV), based on the predicted shear stress from the ANN model. Finally, the performance metrics of the ANN-NLR rheological model were evaluated using the root mean square error (RMSE) and correlation coefficient (R2) and comparison made with the Single ANN rheological model. The results showed the outperformance of ANN-NLR model over the ANN model for rheological parameter prediction, with R2 values of (0.99) for YP and (1) for PV. The predicted PV and YP values were then used for evaluation of transport index (TI) for HCP analysis. The effect of temperature on TI analysis showed this with increase in temperature, TI also increased, indicating the proposed mud providing good HCP under HPHT conditions.

DRILLING MUD THINNER BASED ON TECHNICAL LIGNOSULFONATES FROM WASTE OF CATALYST PRODUCTION

The article presents the results of research on obtaining liquid thinners for drilling muds from waste generated at one of the technological stages in the production of sulfocationic catalysts from technical lignosulfonates.During the production of heterogeneous sulfo-cationic sorbents and catalysts from technical lignosulfonates, acidic waters containing low-molecular-weight fractions of lignosulfonates, residues of hemicellulose hydrolysis products, water-soluble, and extractive substances are generated at the stage of washing off the residual acid. One of the ways to utilize the generated waste could be its further processing into new reagents. Therefore, the aim of this work was to develop a formulation of a thinner based on the generated waste and study its effectiveness in typical drilling muds. A dry industrially produced lignosulfonate was used as a reference reagent.The possibilities of using the resulting liquid waste to obtain highly effective thinners for drilling muds based on lignosulfonates are shown. It is revealed that the resulting reagent reduces the rheological parameters of the drilling mud, is comparable in effectiveness to dry industrially produced lignosulfonate (0.5 % by weight and 1 % by weight), and is technologically easy to use. In fresh water solutions, the modified form of the reagent with the addition of oxyethylidenediphosphonic acid is more effective, while in mineralized solutions the unmodified form is more effective.

Improving the Rheological Properties of Water-based Drilling Muds Using Waste Glass Powder

Improving the Rheological Properties of Water-based Drilling Muds Using Waste Glass Powder

A hybrid inversion algorithm to obtain the resistivity of the uninvaded zone based on the array induction log

This study investigates the impact of the drilling mud invasion on the borehole-measured resistivity. The primary objective is to retrieve the true resistivity of the formation, which helps in identifying different fluids in the reservoir. To achieve this goal, We proposed a hybrid inversion approach integrating the Levenberg-Marquardt and Markov Chain Monte Carlo algorithms with a five-parameter formation resistivity model. Synthetic and real-world data are utilized to assess the method's robustness and reliability. The simulated result indicated that the method is reliable when the data noise level is less than 5%.The method applied to real-world data revealed that the resistivity profile on the water zone showed a slight increase in the inverted resistivity from measured resistivity. Meanwhile, in the oil zone, the calculated resistivity revealed a high deviation from the measured resistivity, indicating the effects of mud invasion. The introduced methods are only applicable when the invasions of mud occur within the range of the logging tool's depth of investigation. Moreover, the method may give no reliable result when the invasion exceeds the tool's investigation depth. It indicates its limitation.

Selection of the optimal formulation of the biopolymer system for the stimulation of productive formations

The object of study in this paper is the biopolymer system «X» – a complex composition that includes a biopolymer, salts and a thermal stabiliser intended for use in drilling fluids at high temperatures. The components of the formulation include complex reagent «X» for regulating structural, mechanical, rheological and filtration properties, as well as inhibitors (sodium and potassium chloride) and filler. Components of the biopolymer system (sodium chloride, organo-mineral colmatant thermal stabiliser) increase its thermal stability. One of the most problematic areas is the mechanism of sodium chloride's thermal stabilising effect. It is associated with an increase in the overall mineralisation of the drilling mud, which leads to a certain conformation of biopolymer molecules, accelerates gelation processes and counteracts the temperature dilution of the system. The results obtained can be explained as follows: – an increase in the concentration of sodium chloride leads to an increase in the ionic strength of the solution, which contributes to a change in the conformation of biopolymer molecules, enhancing intermolecular interactions and, as a result, increasing the viscosity and stability of the system; – the organo-mineral colmatant heat stabiliser promotes the formation of a filtration crust on the well walls, which prevents fluid loss and reduces rock permeability; – all components of the system interact with each other, affecting the properties of the solution. The optimum ratio of components allows achieving the required rheological characteristics and ensuring the stability of the system at high temperatures. As a result of processing the information on technologies for tapping productive horizons, the disadvantages and advantages of each of them were noted. The existing drilling fluid systems used to tap productive horizons at high temperatures were considered. However, more attention was paid to the selection of a new optimal formulation of the biopolymer system, in accordance with the specified rheological and structural and mechanical properties for further implementation in practice. This ensures the possibility of obtaining predictive parameters of the drilling mud. The proposed system has a number of advantages over similar ones, namely: – the system retains its properties at high temperatures; – the system provides the required values of viscosity, filtration and static shear stress; – due to the use of an optimal formulation, high efficiency is achieved at a relatively low cost.

Progress on clay swelling inhibitors: a comprehensive review

Relevance. It is known that swelling of a well wall due to the presence of water negatively affects drilling operations, causing a significant increase in their material costs. The use of various inhibitors prevents this effect and the drilling mud reacting on wellbore narrowing. In this sense, the problems of developing polymer, amino-, ionic liquid and shale inhibitors of surfactants considered in the article are very relevant and of practical interest to oil engineers in terms of the prospects for fundamental and applied researches of these issues. Aim. To study the possibilities of existing approaches and methods that determine the characteristics of the main clay swelling inhibitors, the regularities of changes in the properties of traditional and non-traditional clay materials, as well as the mechanisms of clay swelling with the identification of the most characteristic group of these inhibitors. Object. Processes of minimizing the effect of wall narrowing as a result of exposure to inhibitors. Methods. Systematic, critical and comprehensive analysis of modern data on clay swelling inhibition in the field of drilling muds. Results. The authors have carried out the detailed analysis of clay swelling. The paper discusses the characteristics of inhibitors required to prevent swelling, in the structure of which nitrogen and ionic liquids are contained. It is noted that a high-quality clay swelling inhibitor should include in its base a water-soluble bulk molecule with a distinct hydrophobic and hydrophilic structure; have characteristics, which allow replacing the hydrated cations of the intermediate layer with some hydrophobic cations, such as ammonium ions instead of sodium ions; differ in the ability to disperse multiple cations well. It was found that functional groups that support inhibitor binding to the siloxane groups of the clay are able to significantly expand clay swelling.

Novel application of citric acid based natural deep eutectic solvent in drilling fluids for shale swelling prevention

Swelling of shale in clastic reservoirs poses a significant challenge, causing instability in wellbores. Utilizing water-based drilling mud with shale inhibitors is preferable for environmental reasons over oil-based mud. Ionic liquids (ILs) have garnered interest as shale inhibitors due to their customizable properties and strong electrostatic features. However, widely used imidazolium-based ILs in drilling fluids are found to be toxic, non-biodegradable, and expensive. Deep Eutectic Solvents (DES), considered a more economical and less toxic alternative to ILs, still fall short in terms of environmental sustainability. The latest advancement in this field introduces Natural Deep Eutectic Solvents (NADES), renowned for their genuine eco-friendliness. This study explores NADES formulated with citric acid (as a Hydrogen Bond Acceptor) and glycerine (as a Hydrogen Bond Donor) as additives in drilling fluids. The NADES based drilling mud was prepared according to API 13B-1 standards and their efficacy was compared with KCl, imidazolium based ionic liquid, and Choline Chloride: Urea-DES based mud. A thorough physicochemical characterization of the in-house prepared NADES is detailed. The research evaluates rheological, filtration and shale inhibition properties of the mud, demonstrating that NADES enhanced the yield point to plastic viscosity ratio (YP/PV), reduced mudcake thickness by 26%, and decreased filtrate volume by 30.1% at a 3% concentration. Notably, NADES achieved an impressive 49.14% inhibition of swelling and improved shale recovery by 86.36%. These outcomes are attributed to NADES’ ability to modify surface activity, zeta potential, and clay layer spacing which are discussed to understand the underlying mechanism. This sustainable drilling fluid promises to reshape the drilling industry by offering a non-toxic, cost-effective, and highly efficient alternative to conventional shale inhibitors, paving the way for environmentally conscious drilling practices.

Evaluation of shell powders of bush mango and hamburger bean as eco-friendly fluid loss control additives in water-based drilling mud

The use of agro-based additives in drilling mud to reduce fluid loss and improve the rheological properties of mud has gained enormous attention owing to its biodegradability and low cost. This study evaluates the effects of shell powders of hamburger bean and bush mango as eco-friendly and cheap filtration control additives in water-based mud. Samples were formulated with different concentrations (5 g, 10 g, 15 g, and 20 g) of the shell powders to determine their effects on the filtration and rheological properties of the mud. From the results, both hamburger beans and bush mango shell powders improved the rheological properties of the fluid. Meanwhile, only 15 and 20 g of Bush mango shell powders reduce fluid loss by 10.5 and 13.2%, respectively. Similarly, the addition of 5 g, 10 g, 15 g, and 20 g of hamburger bean shell powders reduced fluid loss by 1.4, 8.82, 14.71, and 20.6%, respectively. Both Bush Mango and Hamburger Beans shell powders based mud produced cake thickness between 1.2 and 1.8 mm. The research demonstrates that Hamburger Beans shell powders provides a progressive decrease in filtration rate as the content increases, and it stand as a cheap and eco-friendly alternative additive for the enhancement of rheological and filtration properties in water-based drilling fluids.

Factors Influencing Radiation Sound Fields in Logging While Drilling Using an Acoustic Dipole Source

With the increasing number of complex well types in the development stage of oil and gas fields, it is becoming increasingly urgent to use remote detection logging while drilling (LWD) to explore the geological structures in a formation. In this paper, the feasibility and reliability of the dipole remote detection of logging while drilling are demonstrated theoretically. For this purpose, we use an asymptotic solution of elastic wave far-field displacement to derive the calculation formula for the radiation pattern and energy flux of an LWD dipole source. The effects of influencing factors, including the source frequency, formation property, drill collar size, and mud parameter, on the radiation pattern and energy flux are analyzed. The results show that the horizontally polarized shear wave (SH-wave) has a greater advantage in imaging the reflector compared with the cases of the compressive wave (P-wave) and vertically polarized shear wave (SV-wave), which indicates the dominance of the SH-wave in dipole remote detection while drilling. The optimal source excitation frequency of 2.5 kHz and inner and outer radii of the drill collar of 0.02 and 0.1 m, respectively, should be considered in the design of an LWD dipole shear wave reflection tool. However, the heavy drilling mud is not conducive to remote detection during logging while drilling. In addition, the reflection of the SH-wave for the LWD condition is simulated. Under the conditions of optimal source frequency, drill collar size, and mud parameters, the reflection of the SH-wave signal is still detected under the fast formation.

Mathematical Model of Drilling Mud Movement along a Shale Shaker Screen

Introduction. When drilling oil or gas wells, rock from the bottomhole is brought to the surface by drilling mud, which is cleaned of sludge by shale shakers at the first stage. Shale shakers are equipped with such a screen and create such trajectories of vibration of the frame in order to solve a dual problem: on the one hand, to provide the cleaning of the drilling mud coming from the well mouth, and on the other hand — to maintain the proper degree of cleaning. To correctly select the nomenclature of screens, it is necessary to reliably determine the throughput capacity of a shale shaker in the real-time setting. This will allow you to pre-order the required number of screens with the required cell size. Previously, studies were conducted by sieving a mixture of calibrated granules on a standard shaker or by straining mineral oil through a fixed screen. However, this does not fully correspond to the actual conditions of drilling mud screening. The objective of this article was to simulate the throughput of a drilling shale shaker under real conditions by calculating the movement of drilling mud along a vibrating screen using its previously obtained specific throughput capacity.Materials and Methods. When creating a mathematical model of the full throughput capacity of a shale shaker, a previously known mathematical model of fluid flow in an open channel and a finite-dimensional approximation in the form of a sequence of sections of concentrated containers connected by hydraulic conductivities (by analogy with the approximation of long electrical lines and extended gas pipelines by the finite element method) were used. The fluid flow rate over the screen was determined according to Chézy law. In this case, the cross-sectional area of the flow above the screen for a specific section was specified as the arithmetic mean between the initial and final values of the drilling mud height in the corresponding section.Results. A chain calculation scheme for sieving drilling mud was compiled. Based on the material balance, mathematical models were developed for determining the throughput and height of drilling mud above the screen: for the first section of the screen and the first nodal point of the screen; for subsequent screen sections and subsequent screen nodal points; for the last section of the screen and the last nodal point of the screen.A mathematical model of the drilling mud movement along the shale shaker screen has been obtained, which, due to the finite-dimensional representation of this flow along n sections of the screen length, is a system of n integral equations describing concentrated tanks, and n – 1 algebraic equations describing the flow of drilling mud between tanks.Discussion and Conclusion. The movement of drilling mud along the length of the shale shaker screen corresponds to the movement of a steady uneven flow in an open channel. However, in the first case, the volume flow along the length is variable (decreasing to zero), and in the second case, it is constant along the length. Therefore, the use of only one differential equation for steady uneven flow in an open channel is not sufficient in this case. The resulting mathematical model of the drilling mud movement along the shale shaker screen is a mathematical basis for the development of a modeling program to determine the throughput of the shale shaker for real operating conditions, i.e., for a specific drilling mud, a given screen or a given drive system of the shale shaker.

Utilizing Environmentally and Recycled Materials to Formulate Drilling Mud

It is important to pay attention to environmental regulations while preparing drilling mud because it has become aspects that must be taken into consideration both now and in the future. It is essential to use sustainable and environmentally friendly materials at every stage of the oil and gas industry if possible in order to ensure high standards of sustainable practices. Oil that has been used to prepare oil base mud have bad impact on soil and human at the same time. The using of flaxseed oil instead of gas oil to preparing emulsion is done in this paper. The results were encouraging, and showed the possibility of using flaxseed oil for preparing ecological emulsion. The efficacy of walnut shell powder as an emulsifying agent has been tested as a surface tension reducer and the possibility of using it to increase the stability of an oil emulsion either in reverse or direct at high temperatures (400°F). This research includes measurements of filtration, stability and rheological properties of oil emulsion under laboratory and high temperature. Sample C showed high stability less than 3% because it is a direct emulsion composed of 10% flaxseed oil and crushed walnut shells, which acted as an excellent emulsifying agent because it was composed of cellulose with a percentage of more than 40%. Sample E gave the highest viscosity values, and the reason for this is that it is a reverse emulsion consisting of 60% flax oil with a high viscosity, as it reached more than 70 centipoises at 400 degrees Fahrenheit.

Enhancing Detection and Mitigation of Toxicity in Marine Biota from Drilling Activities

The growing demand for petroleum-based energy has significantly contributed to environmental pollution, particularly in the oil mining industry. This study aims to evaluate the toxicity of oil drilling mud on marine biota, using tiger shrimp (Monodon peneus) as bioindicators. The shrimp were exposed to various mud concentrations (100%, 50%, 25%, 12.5%, 6.25%, 3.25%, 1.25%, and 0%) and observed over time intervals of 0, 24, 48, 72, and 96 hours. The methodology involved direct observation of the shrimp's survival rates at each mud concentration. The results revealed a significant decline in survival rates at higher mud concentrations, with a strong positive correlation (r = 0.81) between mud concentration and toxicity. The pH levels remained stable and alkaline (7.81–8.28), while turbidity at lower concentrations (6.25%) was within acceptable limits after 96 hours, with a strong correlation (r = 0.73). These findings underscore the importance of stringent monitoring and management of drilling mud disposal to safeguard marine ecosystems, aligning with Sustainable Development Goal (SDG) 14: Life Below Water.

Increasing the Thermal Resistance of Water-Based Mud for Drilling Geothermal Wells

Energy demand and growing environmental concerns have fueled increased interest in geothermal drilling in recent decades. The high temperature and pressure in the boreholes present significant challenges to drilling, particularly in terms of the selection of suitable drilling mud, cement slurry, and drilling equipment. Drilling mud is regarded as one of the primary factors that affect the cost and success of geothermal drilling. This paper presents experimental studies aimed at assessing the thermal stability of drilling muds for geothermal drilling. Research on the antidegradation of polymers contained in drilling muds is presented. The thermal stability of drilling fluids was evaluated on the basis of changes in rheological and filtration parameters under the influence of a temperature of 160 °C. Attempts were made to increase the thermal resistance of drilling fluids by using antioxidants and glycol compounds. The effectiveness of increasing the thermal resistance of muds by adding synthetic polymers, nanomaterials, and graphite was tested. A new way of increasing the thermal resistance of drilling muds by using fatty amine compounds in combination with the amine agent ‘TEA’ was proposed. Tests showed that the addition of polyglycol and the antioxidant agent sodium ascorbate to the mud did not protect the polymers from decomposition at 160 °C. There was no effect of increasing the thermal conductivity on improving the thermal resistance of the scrubber. Based on the analysis of results from laboratory tests, a composition of a water-based drilling mud without bentonite was developed for drilling geothermal wells. The developed drilling mud is characterized by thermal resistance up to 160 °C, stable rheological parameters, low filtration, and appropriate thermal conductivity characteristics.

Heavy Metals, Polycyclic Aromatic Hydrocarbons, Total Petroleum Hydrocarbons and Total Hydrocarbon Contents in Drilling Mud Effluents From Eastern Obolo Oilfield In The Niger Delta Region Of Nigeria

The objective of this paper is to evaluate the concentrations of heavy metals, polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbons (TPH) and total hydrocarbon content (THC) in drilling mud effluents from Eastern Obolo Oilfield in the Niger Delta region of Nigeria using appropriate standard methods. The TPH and THC of OBM and WBM analyses with UV-Vis spectrophotometer indicated 1.60 mg/kg for OBM and 1.30 mg/kg for WBM. A value of 5.35 mg/kg was obtained for OBM compared to 5.15mg/kg for the OBM in the THC. Generally, the result indicated that TPH<THC and was found to be far lower than 50 mg/kg allowable for drilling mud in the environment. GC-MS analysis for TPH indicated a range of n- alkanes with a higher concentration (46118.28 ug/l) in the OBM compared to WBM concentration (17185.95 ug/l) compared to the UV-Vis spectrophotometer. The analysis of TPH using GC-MS revealed a more comprehensive range of n- alkanes present in the OBM and WBM. The heavy metals indicated considerable differences of the concentration in OBM and WBM. The concentrations viewed significantly with the range for the WBM; Fe>Zn>Cr>Pb>Cu>Ni>Cd. The concentrations range in the OBM were; Fe>Cr>Zn>Ni>Cu>Pb>Cd. The evaluation of the concentrations of these elements in drilling mud are of environmental significance from pollution viewpoint especially ferrochrome lignosulphate (Chromium pollution) and lead compounds (lead pollution). The results from this study which indicates the presence of varying concentrations of heavy metals and petroleum hydrocarbons in the drilling mud is valuable and significant when making the choice for subsequent disposal of drilling mud effluents and, particularly in the study area where extensive oil/gas operation is ongoing.

Wireless transmission method of electromagnetic wave of cross screw signal

Abstract Based on the near-bit azimuthing gamma measuring instrument developed by Changqing Drilling Company, this paper uses comsol multiphysics(COMSOL) numerical simulation software to build the electromagnetic wave wireless transmission model of cross-bolt signal while drilling. By using finite element method and a large amount of calculation and analysis, the influence law of source distance, drill wire conductivity, borehole and mud conductivity and other parameters on the response characteristics is obtained. The simulation modeling method presented in this paper and the conclusions obtained have important guiding significance for further optimizing and upgrading the near-bit wireless short-pass device and better understanding and mastering the signal transmission law of this kind of instrument.

Exploring the Performance of Dry Bamboo Leaves Powder from Bambusa Heterostachya as Additive in Water-Based Mud

In the evolving landscape of petroleum drilling, the quest for eco-friendly alternatives to traditional mud additives is paramount. This study explored the performance of Dry Bamboo Leaves Powder (DBLP) from Bambusa heterostachya as an additive in water-based mud. Dry Bamboo Leaves were obtained, crushed, and then sieved to 106-micron size. Mud properties, including mud weight, plastic viscosity, yield point, gel strength, mud cake thickness and filtrate volume were examined under fresh conditions by integrating different concentrations of DBLP (3.5 g, 7.0 g, 10.5 g, and 14 g). The laboratory experiments adhered to the standards set by the American Petroleum Institute (API). The introduction of DBLP concentrations resulted in a reduction in the alkalinity and mud weight of the drilling mud. Additionally, the drilling mud's yield point and plastic viscosity were altered at different DBLP concentrations. The inclusion of DBLP enhanced the gel strength and decreased filtrate volume while maintaining the same mud cake thickness.

Retraction of "On Improving Water-Based Drilling Mud Swelling Control Using Modified Poly(Vinyl Alcohol)s".

[This retracts the article DOI: 10.1021/acsomega.3c08317.].

3D DEM investigation on macro-meso mechanical responses of gas hydrate-bearing sediments in process of unloading confining pressure

Well drilling, gas production, and reservoir stimulation can disrupt stress states of gas hydrate-bearing sediments (GHBSs) surrounding wellbores, potentially inducing wellbore instability due to confining pressure unloading. Therefore, it is very important to know about the macro-meso mechanical responses of GHBSs under an unloading confining pressure path (UCPP). Herein, a discrete element method (DEM) was used to perform triaxial tests on three-dimensional numerical GHBSs under the UCPP and a conventional drained path (CDP) to bridge the knowledge gap. Results show that GHBSs under the UCPP are more prone to failure and dilatation than under the CDP, due to the reduced bearing capacity of contact force chains, relatively unstable particle assembly, and rapid cementation breakage development. Additionally, the stress path has little effect on the cohesion and friction angle of GHBSs. Furthermore, under the UCPP, the failure and dilatation risk of GHBSs are positively correlated with unloading confining pressure rate, inversely related to hydrate saturation and initial effective confining pressure. The grey relational analysis illustrates that compared to hydrate saturation and initial effective confining pressure, the unloading confining pressure rate minimally affects the unloading confining pressure effect. These findings can serve for experimental studies and field applications (e.g., optimizing drilling mud density, sand production rate, and fracturing fluid flowback rate) concerning the unloading confining pressure responses of GHBSs.

Experimental investigation on high voltage electric pulse rock breaking under drilling mud conditions

High voltage electric pulse rock breaking technology is a novel and promising rock breaking technique that is environmentally friendly, efficient, and nearing industrial application. However, the drilling performance of electrode bits under varied drilling muds and the mechanism of high voltage electric pulse rock breaking remain unclear. This study entails real drilling experiments conducted on red sandstone using electrical pulse drilling (EPD) under different initial voltage peaks, electrode bits, and drilling muds to investigate the impact and mechanism of EPD. A laboratory experimental system for high voltage pulse rock breaking is established based on a 0–80 kV EPD pulse generator. Three types of electrode bits are devised, namely, petal-structural, four-point-structural, and circular-ring-structural electrode bits. The EPD experiments on red sandstone are executed under seven different drilling muds at initial peak voltages ranging from 13 to 17 kV. And the efficiency of EPD rock breaking is assessed using five quantitative indexes: rate of penetration, breaking volume, specific energy of rock breaking, and the proportion of electrical fragmentation and hydraulic-electric rock fragmentation. Furthermore, the physical parameters, i.e., density, conductivity, Zeta potential, PH, and apparent viscosity, of the seven drilling muds are measured, shedding light on the rock breaking mechanism of EPD under specific drilling mud conditions. Subsequently, the designed electrode bit is evaluated, and based on experimental phenomenon, structural optimizations of the electrode bit and EPD drilling recommendations under various drilling mud conditions in real drilling scenarios are proposed. This research is poised to offer valuable insights into the design of EPD electrode bits and the selection of drilling mud for enhancing drilling efficiency.