Static Filtration Research Articles

Enhancing drilling efficiency: An experimental study on additives for mud loss mitigation in fractured media

Drilling in fractured formations poses a substantial challenge due to mud loss, which not only impedes operations but also leads to substantial costs and delays. Effectively controlling mud loss is crucial for efficient drilling. However, determining the appropriate mud additive to minimize mud loss in fractured formations requires further investigation. This is because proper mud additives can assist in sealing fractures, preventing wellbore instability issues and minimizing formation fluid influx. This study aims to investigate mud loss in fractured porous media by evaluating three additives' performance using an experimental setup that provides different fracture apertures. This setup provides an accurate simulation of down-hole static filtration at high pressure/temperature by flowing pressurized mud through fractured porous media and measuring effluent under different scenarios. The particular focus is on preformed particle gel (PPG), walnut shell, and shell additives. The study examines the effects of these additives, their particle sizes, and their mixture effect on mud loss. An optimal concentration of 8000 ppm of PPG, as well as larger particle sizes (mesh No.200) of walnut shell and shell, are found to be more effective in controlling mud loss, reducing mud loss by 34.4%, 110%, and 20.85%, respectively, compared to the base mud. The results reveal that when mud contains only one additive, the walnut shell is the most effective, reducing the volume of mud loss from 394.2 cc to 150.2 cc, while a mixture of PPG-shell-base mud at elevated temperatures represents the highest performance of additive combinations. The PPG-shell-base mud significantly reduces mud loss from 394.2 cc to 115 cc and 27.8 cc at 50 °C and 80 °C. In conclusion, this research not only contributes valuable insights to the field but also offers practical recommendations for the use of additives to effectively control mud loss during drilling operations in fractured formations, ultimately improving drilling efficiency and cost-effectiveness.

A comparative study of the water based drilling fluid viscoelasticity versus shear viscosity effects on the filtration loss control

Drilling fluid shear viscosity and the elasticity are two of the most influential factors controlling the volume of fluid invasion into reservoir and the resultant formation damage. Previous studies were inconclusive regarding individual effects of the fluid shear viscosity vs elasticity, mainly because of the difficulty to separate and measure their impacts independently. In this study, two groups of fluids were formulated: one group with the same shear viscosity and variable elasticity and the other group with the same elasticity and variable shear viscosity. Detailed rheological characterizations were carried out by conducting amplitude sweep and controlled shear rate tests. Viscoelastic properties were quantified in terms of the energy dissipation. Static filtration tests and core flooding experiments were conducted to determine the static fluid loss, pressure drop across the core at different fluid flow rates, and the resultant formation damage induced by each fluid. The observations from this study provided several key insights: i-) The static filtration rate can be more effectively controlled by altering fluid viscoelasticity than the fluid shear viscosity; ii-) Both the shear viscosity and the elasticity strongly influence the pressure drop across the core, however, the effect of the fluid elasticity on the pressure drop is more pronounced; iii-) Increasing the fluid elasticity inhibits fluid invasion into the formation more effectively than increasing the fluid shear viscosity; iv-) The fluid elasticity can be effectively used for developing non-invasive fluids, which would reduce static filtration rate, increase pressure drop, and minimize formation damage by effectively reducing fluid invasion.

Study on Plugging Microfracture by Using High-Temperature Emulsified Bitumen

A new kind of modified emulsified bitumen used to plug a microcrack was studied. The sizes of high-temperature emulsified bitumen were fit for the sizes of the microcrack, which were approved by the scanning electron microscope and laser particle size analyzer. Some tests have been designed to demonstrate that the polymer could be used to promote the softening point of modified asphalt, and the high-temperature emulsified bitumen has also shown an excellent performance in terms of static filtration, the viscous coefficient, and extreme pressure lubrication, as well as to inhibit ting shale expansion. The permeability recovery could reach 88.26%, which meets the specification requirements. The mud cake, which was formed by high-temperature emulsified bitumen as an additive, was thin, tough, and dense, which was proved by the scanning electron microscope. The process used to obtain this additive was simple, and the performance of the plugging microfracture was excellent, so this kind of plugging agent could have a better application future.

Study on the Performance of Drilling Mud Affected by High Temperature Emulsified Bitumen

The performance of drilling mud influenced by high temperature emulsifier bitumen (HTEB) was studied in this paper. With high temperature emulsifier bitumen as mud additive, the Apparent viscosity (Av), Plastic viscosity (Pv) and Yield point (Yp) of drilling mud were increased before or after aging. The modulus particle size and average particle size of drilling mud were increased. Comparing with the particle sizes before aging, the particle sizes turn small and the rheological property change for the better after aging. The mud cake was thin, toughness and dense. The toughness of mud cake was increased, as high temperature emulsifier bitumen added. The surface of sandstone core and shale core were enwrapped tightly by high temperature emulsifier bitumen and there no crack appeared in the surface of core. The static filtration was 18.8 ml. The film could be form at the surface of debris, because of the high temperature emulsifier bitumen had adhesion.

Experimental investigation of filter cake deposition under cross-flow and static filtration conditions

Effects of cross-flow velocity, filtration pressure, and solid concentration on filter cake properties are studied by using a new filtration setup that allows performing filtration tests under a wide range of operating conditions. The main feature of this setup is that pressure and cross-flow velocity are decoupled, so it was possible to independently investigate the effect of these variables on filter cake properties. Filtration tests have demonstrated that particle invasion into filter media pores occurs initially, leading to the formation of an external filter cake. The increased cross-flow velocity creates an erosive shear stress at the surface of the external cake, which limits cake growth, indirectly maintaining a high filtrate flow rate. This high filtrate rate imparts a considerable drag force onto suspended particles, driving a high count into the porous substrate where these particles could deposit. Increasing pressure amplifies this internal particle deposition, particularly where there is no or limited external filter cake to limit filtrate drag and screen particles at the cake surface. The effect of cross-flow velocity on pore blocking and filter cake structure is observed and demonstrated by CT scanning and scanning electronic microscopy.

Research and application of construction technology of digital mud cake formed by drilling fluid filtration

In drilling engineering, mud cake is formed when drilling fluid invades the near-wellbore zone, which can reduce drilling fluid leakage and reservoir pollution and maintain wellbore stability. To study the three-dimensional spatial characteristics of mud cakes, such as heterogeneity, particle accumulation, and porous media, CT scan images of cores and mud cakes before and after drilling fluid intrusion are used as the research object. The composite filtering and segmentation method for typical regions of images based on grayscale values and the batch segmentation method for large regions of images based on deep learning are investigated. On this basis, a visualized digital mud cake is constructed, and microscopic evaluation indexes such as the percentage, equivalent radius, throat length, sphericity, and coordination number of pores and particles in the mud cake are established. The application results show that the number of isolated pores in the outer mud cake formed by static filtration of drilling fluid is more than that of dynamic ones, the connectivity of pores is poor, and the particles have a better sealing effect on pores. The combined effect of the outer and inner mud cake results in different effects on core intrusion. The construction technique of digital mud cake can study the structure at a micron scale. This technique can provide more detailed guidance for engineering situations, such as optimization of drilling fluid systems in fractured formations, damage evaluation of reservoirs by drilling fluid, and influence of mud cake on cementing quality.

Rupture resistance of filter cake under static filtration using a novel experimental technique

A novel apparatus is used to quantify the filtration characteristics of water-based drilling fluids and rupture behaviour of external filter cake. Under static filtration, the filtration pressure (400 to 800 kPa), time (15 to 60 min), the particle size distribution of the weighing agent (D50: 11 to 136 µm) relative to the pore size distribution of the substrate (S50: 14 and 65 µm) and the type of weighing agent (CaCO3 or BaSO4) play an important role in governing the porosity, thickness, and the rupture resistance of filter cake. With an increase in D50 of mud, the normalised rupture resistance reduces by about 20% irrespective of the increase in the external filter cake thickness. Further, the viscosity of the filtrate increases with D50 indicating the retention of less xanthan gum in the filter cake. The denser barite particles form a thinner and tighter cake, which exhibits higher resistance to rupture.

Improved filtration parameters from modified API filter press

Static filtration tests carried out by using the API filter press have been extensively used to assess drilling fluid filtration performance in terms of filter cake design. However, this test does not address many aspects of the filtration process such as the invasion of the particles into the substrate, the time the external filter cake starts forming and the effect of the pore throat size of the substrate. This is because the API filter press is designed to use as substrate filter paper with a pore throat smaller than the solid particles size in the drilling fluid. Here it is shown that by a simple modification of the base cap of the API filter press it is possible to use thick porous disks with pore throats larger than the solid particle size in the drilling fluid. This simple variation allows a better investigation and understanding of the filtration process and drilling fluid performance.

Development of a Solvent-Compatible High-Throughput Static Filtration Test Equipment

A novel laboratory equipment has been constructed to allow research in the development of solvent-resistant and solvent-tolerant nanofiltration applications. The equipment can control six parallel lines while concurrently feeding different solvents or mixtures of solvents over membrane samples housed in individual dead-end cells. Control feedback between the solvent flow (up to 40 g h–1) and pressure developing over the membrane sample (up to 40 bar(a)) is realized independently for each line. The feedback enables one to set experiments in either a constant-flow or constant-pressure operation mode. At all times, the temperature of the process (up to 80 °C) is controlled and referenced for an accurate evaluation of the apparent permeability, accounting for changes in the physical properties of the used solvent (i.e., viscosity and density). The test equipment can be employed in long-term operations, initially following changes in the permeability of a fresh membrane during preconditioning (washing, swelling, and/or compacting), with subsequent process studies assessing the properties of the settled polymeric structures relevant in filtration.

Hydrodynamic Analysis and Cake Erosion Properties of a Modified Water-Based Drilling Fluid by a Polyacrylamide/Silica Nanocomposite during Rotating-Disk Dynamic Filtration.

In this study, the potential of using a polyacrylamide-silica nanocomposite (PAM-S) to control the filtration properties of bentonite water-based drilling muds under different salinity conditions was evaluated. Static filtration tests under low-pressure/low-temperature (LPLT) conditions accompanied by rheological measurements have been carried out to analyze the role of silica nanoparticles (NPs) and nanocomposites (NCs) in the base fluid properties. Moreover, high-pressure/high-temperature (HPHT) static filtration was also investigated to evaluate the thermal stability of PAM-S. Afterward, dynamic filtration has been conducted in a filtration cell equipped with an agitating system with a disk-type impeller to investigate the hydrodynamic and formation of a filter cake under shear flow conditions. Fluid flow velocity and wall shear stress (WSS) distribution over the filter cake were analyzed using an exact 3D computational fluid dynamic (CFD) simulation. A transparent filtration cell with a camera was used to accurately record the fluid flow field inside the filter press and validate the CFD results. The obtained results indicated that adding silica NPs at a concentration of less than 2 wt % increases the fluid loss due to reducing rheological properties such as yield point. While silica NPs could not significantly change the mud properties, the experimental results showed that, under both LPLT and HPHT conditions, the PAM-S NC could reduce the total filtration loss by 70% at a low concentration of 0.75 wt %. Moreover, during dynamic filtration, the results indicated that there is a linear relationship between the cake thickness and the inverse of WSS at different operating pressures. However, no correlation could be found between predeposited mud cake erosion and WSS. At a rotating disk speed of 1000 rpm, more than 60% of the predeposited mud cake was eroded after 30 min for a saline mud sample while for the NC-treated mud sample cake erosion is considerably reduced and reaches up to 20% at 1.5 wt % PAM-S.

New insight into hydrodynamic and cake erosion mechanism during rotating-disk dynamic microfiltration of concentrated bentonite suspensions at different salinity conditions

The present study investigates the dynamic filtration of concentrated slurry fluids containing colloidal clay particles under different salinity, shear flow, and flux rate conditions. The dynamic filtration study was carried out by the filtration cell equipped with a rotating disk to apply shear stress over the membrane surface. A 3D CFD simulation has been implemented to model the hydrodynamic flows inside the filtration cell to obtain the wall shear stress (WSS) on the membrane surface at different disk rotation speeds. The thickness and surface patterns of fouling were captured utilizing a surface profilometer. First, the cake-filtration model was used to predict the flux rate and fouling thickness under static filtration. Then, the corresponding filtrate flux at stabilized cake thickness under shear flow conditions was calculated. The results showed that increasing the suspension salinity causes the reduction of rheological properties and increases the cake permeability due to the compression of the electrical double layer around clay particles. The results also revealed that increasing the flux rate condenses the cake and reduces erosion. Finally, a model for predicting the rate of fouling removal during dynamic filtration was developed using nonlinear regression. The results showed that a sigmoidal function with appropriate accuracy (R2>0.96) could describe fouling thickness patterns with WSS. Moreover, the mean cake thickness decreased by 80% as the WSS increased from 0 to 2 Pa, where the rotating disk speed increased from 0 to 500 rpm.

The Effect of Weighting Agents on Sandstone Formation Damage from Water-Based Drilling Fluids

Summary Chemical properties of a fluid used in oil and gas drilling operations are critical as they directly affect drilling performance and, most importantly, formation damage in production zones. The increased requirement for high-density fluids to maintain deeper, more complex well trajectories may translate to an increase in drilling fluid solids content when brine-weighted fluids are not compatible or readily available, as more weighting materials are added to increase density and control formation pressures. However, these weighting agents can also plug pores and cause formation damage, leading to significantly reduced productivity and the need for remediation. The objective of this study is twofold: To evaluate and compare solids invasion and damage characteristics and performance of different weighting materials in water-based reservoir drilling fluids (RDFs) and to study the solubility behavior of micronized ilmenite in different acid systems. Several fluid systems were prepared using weighting agents differing in size, morphology, and chemical nature, primarily American Petroleum Institute (API) barite, micronized barite, and micronized ilmenite. Rheological properties were measured and high-pressure/high-temperature (HP/HT) static filtration experiments were conducted to investigate filtration behavior and filter-cake thickness. A modified coreflood setup was used to simulate dynamic drilling conditions downhole and accurately measure the effect of solids on formation damage. Computed tomography (CT) scan analysis provided the extent of the damage associated with each weighting agent. Within the scope of the study and limits of the experimental setup, results showed that the formation damage created by micronized ilmenite is much lower, compared to API and micronized barite in Bandera, Berea, and Boise sandstones. HP/HT solubility reactions with different blends of acids were monitored. The best acid system was tested with a complete drilling fluid system using the mud loop to ensure the ability to remediate damage from drilling operations.

Evaluating sealability of blended smart polymer and fiber additive for geothermal drilling with the effect of fracture opening size

Geothermal formations often contain extensive fracture networks. These fracture networks contribute to the significant loss of drilling fluids during geothermal drilling. Multiple loss circulation materials (LCM) such as fiber, granules, and pills have been proposed to tackle this problem but with only limited success. Recent advances in materials science have led to the development of thermoset shape memory polymers (SMP) to address the lost circulation problem. In this paper, we evaluate a thermoset SMP performance in sealing near wellbore fractures of different sizes in geothermal wells. The SMP performance was assessed using granite disks and cylindrical granite cores having fracture sizes of 1000 μm and 3000 μm. A static filtration test was performed using cedar fiber, CaCO3, and SMP. Results showed cedar fiber performed better than the CaCO3., reducing fluid loss by 89% and improving sealing pressure by 200 psi. A novel dynamic testing unit that allows for high-temperature testing under flowing conditions was used in this study. The analysis showed that 3% by weight SMP and fiber blends could bridge and plug the 1000 μm fracture. For a larger fracture of 3000 μm width, there was a need to increase the weight concentration of the SMP to 6% to plug the fracture opening effectively. We showed the influence of key parameters such as the type of LCM, concentration, and particle size distribution in optimizing the performance of drilling fluid loss treatment.

Filtration and structure of bentonite-β-cyclodextrin polymer microspheres suspensions: Effect of thermal aging time

Effective filtration loss control is a challenge for water-based drilling fluid when drilling high temperature and high pressure (HTHP) formations. After thermal aging at 200 °C for varying times, the static filtration loss controlling capabilities of β-cyclodextrin polymer microspheres (β-CDPs) and synthetic polymer Driscal-D in bentonite suspensions were compared in this study. A comprehensive physicochemical characterization was presented using Fourier transform infrared (FT-IR), X-ray diffraction (XRD), particle size distribution, zeta potential, electrical conductivity and scanning electron microscope (SEM). The results indicated that when exposure to thermal aging of 200 °C, the filtration loss of bentonite suspension increased with the initial 6 h of aging, after that it increased slightly. While for synthetic polymer Driscal-D, the filtration loss increased gradually with thermal aging time until to 36 h. In contrast for β-CDPs, the filtration loss increased firstly and then decreased and maintained relatively stable after thermal treatment for 6 h. High temperature destroyed the hydrated structure of bentonite particles and induced the increase of filtration loss volume. In viewing of Driscal-D, degradation of the polymer in combination with dehydration of bentonite particles led to the gradual losing of suspensions stability. For β-CDPs, after aging of 6 h, the hydrothermal carbonization reaction generated numerous nano and micro carbon spheres and bentonite-carbon sphere composited structures, which fill in the gaps between the larger particles and contribute to reducing the filter cake permeability. This result identified that β-CDPs are superior to synthetic polymer Driscal-D in filtration control when subjected to long term high temperature environments.

Numerical study on filtration law of supercritical carbon dioxide fracturing in shale gas reservoirs

AbstractSupercritical carbon dioxide (SC‐CO2) fracturing can form more complex fracture network and avoid reservoir damage, making it a lucrative alternative to hydraulic fracturing in shale gas reservoirs. This study establishes a two‐dimensional dynamic filtration model of SC‐CO2 fracturing, which considers stress sensitivity, fluid adsorption, dynamic changes of fluid physical parameters, and coupled fracture propagation. According to the established model, the dynamic filtration of fracture elements and matrix pressure variation in fracture propagation are simulated and analyzed. And the influence of dynamic and static filtration model, constant and variable SC‐CO2 physical parameters, and fluid types in the filtration areas on the calculation results, as well as the effects of stress sensitivity and fluid adsorption on the filtration process are analyzed. The results show that during the fracturing process, fracture elements’ average filtration rate gradually drops and finally becomes stable, while the cumulative filtration volume increases nearly linearly. The static filtration model of uncoupled fracture propagation or the simplification of fluid in the filtration areas to SC‐CO2 single phase provides the reduction of calculation results, while constant SC‐CO2 physical parameters or the fluid simplification to the methane (CH4) single phase have the opposite effect. Stress sensitivity can accelerate the filtration, while fluid adsorption can slow down the filtration. The influence of stress sensitivity is maximal at the middle stage of fracturing, while the influence of fluid adsorption weakens with time. This study's findings have important guiding significance for the optimal design and field application of SC‐CO2 fracturing in shale gas reservoirs. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.

Reducing the membrane fouling in cross-flow filtration using a facile fluidic oscillator

Membrane fouling is a main factor that hinders the wide spread adoption of membrane filtration process. In this study, we demonstrate that a passive fluidic oscillator can effectively reduce the fouling and enhance the permeate flux in cross-flow microfiltration. The oscillator produces a pulsating flow of frequency 56–115 Hz and pressure amplitude 500–700 kPa, which leads to transient high shear rates, surface scouring and back-flushing effects. As a result, it mitigates the concentration polarization, prevents micropores clogging, and inhibits the formation of fouling layer. Its applications for filtration of an inorganic particulate suspension and an organic macromolecular solution, as well as the effect of the operating pressure of the oscillator and the membrane material were investigated. In comparison with the static filtration, the membrane fouling was significantly reduced for both the feed solutions using the oscillator. The current method was further tested for recovery of bacterial capsular polysaccharide from 100 L of pneumococcus fermentation broth. The recovery ratio was improved from 2.0% to 39.3% using the conventional method to around 100% with the oscillator. The process time was also greatly reduced by 30%. Furthermore, though the oscillator provides dynamic filtration, it works under constant pressure without the need of additional motors and stirrers. Potentially, it could be applied to some currently existing filtration systems, to improve the flux performance but without increasing too much the system complexity.

Reparameterization of static filtration model of aqueous-based drilling fluids for simultaneous estimation of compressible mudcake parameters

To mitigate the fluid invasion and the loss of circulation, drilling fluids are designed to provide a thin mudcake with low permeability. Among the many methods of determining the mudcake properties, the absence of proper procedures related to the estimation of mudcake parameters that also consider the experimental uncertainties is noticed. Besides, the non-Newtonian rheological behavior in filtration and its consideration in resistive force modeling is still lacking in the literature. This paper proposes a new methodology of parameter estimation using the particle swarm optimization technique with a modification of the classic model approaches considering the non-Newtonian fluid filtration theory, including the fluid phase rheological behavior. Static filtrations were performed in an HTHP filtration cell with non-Newtonian suspensions with concentrations like those used in actual drilling processes. The internal structure of the mudcakes was studied by SEM images. A reparameterization of the static filtration model was proposed for the simultaneous estimation of precise and uncorrelated parameters: filter resistance, permeability, and compressibility of the mudcakes, considering two different methodologies, Method I – classic and not advisable - and Method II – rigorous statistical process and pressure-dependent filtration properties. As shown in this research, the confidence intervals for all parameters obtained by Method II were narrow with significative statistical meaning, at a confidence level of 95%, and close to those obtained by other authors. Also, the reparameterization procedure removed the parametric correlation between the mudcake permeability and compressibility, resulting in parameters with null correlation. The numerical solution does not lead to a high computational cost and could be installed in an onboard control device to predict online filtration loss, providing valuable pieces of information in oil drilling processes.

Study of materials to combat loss of circulation in fractures and static filtration

For the obstruction and reinforcement of permeable rocks (pores and or fractures), materials to combat loss of circulation (LCMs) are commonly used in the drilling fluid. LCMs, when forming bridges, support and seal rocks, with the objective of preventing drilling fluid from reaching the reservoir. In this study, drilling fluid formulations were developed using full four-level factorial design (DOE), with a central point (4 ^ 2 + 3) in order to evaluate the effect of drilling fluid components on their rheological properties and in the loss of circulation. The tested fluids were prepared using carboxymethylcellulose polymer (CMC), bentonite (BT) as a thickener, and the materials used to combat loss of circulation were used with diatomaceous earth (DE) and hydrogel (HG). The density and pH of all fluids were adjusted to approximately ≈1.14 g/cm−3 and 8.5, respectively, being named F(CMC)BT-DE-HG. The filtration experiments were performed in a HTHP (high temperature, high pressure) filtration cell and the fracture was sealed in a physical simulator, called Fracture Flow Simulator (SEF). The rheological data were adjusted using the Herschel Bulkley model. The incorporation of LCMs in the drilling fluid improved the rheological properties. The results indicated that the investigated factors CMC, BT and HG had the main effects in combating the loss of circulation in the fracture and filtration phases. Diatomaceous earth was not significant in filtration and fracture tests. Finally, based on rheological tests, it can be inferred that the interaction of HG*CMC and BT*CMC is highly significant in combating loss of circulation. The fluid with lower DE level showed superior performance, as it sealed the fracture in 1 min of testing and a low volume of filtrate was observed in the test.

Effect of Carbonate Additives on Dynamic Filtration Index of Drilling Mud

Filtration index of the drilling fluid is an important parameter of well drilling, especially at drilling-in the reservoirs. Standard parameter in the study of drilling fluids is static filtration index. At the same time, it is more feasible to determine dynamic filtration index, if considering actual conditions of the well. Use of polymer carbonate-weighted drilling fluids is advisable at drilling-in oil and gas formations; but, it is also necessary to take into account fractional composition of the weighting agent. Aim of the work is to study the influence of weighting-bridging agent's fractional composition on drilling fluid's dynamic filtration index. Taking into account main theories of bridging agent selection, such as the theory of Abrams, Kaeuffer and Vickers, will make it possible to define the influence of carbonates “blend” on the filtration losses of the drilling fluid. Dynamic high pressure high temperature (HPHT) filter was used in this research, which allows measuring filtration properties of the drilling fluid as in standard HTHP test, with fluid circulating inside the cell. In order to get results that are closer to real conditions, in addition to the standard paper filter, studies were carried out on ceramic disks with a known porosity. Theories on selection of bridging agents considered in the paper have their advantages and disadvantages. Depending on available data on the reservoir (for example, data availability on porosity and permeability) and access to high-quality bridging material, a more effective theory is chosen and the negative effect of the drilling fluid on the productivity of the formation is reduced.

Evaluating the locally sourced materials as fluid loss control additives in water-based drilling fluid

In the exploration for hydrocarbons, a successful drilling operation to the desired depth hinges on the effective performance of the formulated drilling fluid. Apart from carrying drill cuttings to the surface, another major function of the fluid is to seal off the walls of the wellbore to prevent fluids from coming into and out of the wellbore while drilling a well. Numerous commercial fluid loss additives: carboxymethyl cellulose (CMC), polyanionic cellulose (PAC), among others have been in existence with their drawbacks and effect on the total drilling cost. This study evaluates the use of locally sourced materials: Detarium microcarpum, Brachystegia eurycoma and rice husk, as fluid loss control additive in the water-based drilling fluid. The materials were prepared, ground and sieved to 125 microns. Four sets of water-based drilling muds were formulated using the local materials and CMC as fluid loss control additives. The mud formulation was based on the American Petroleum Institute (API) standard of 25g bentonite to 350mL of water. Also, the filtration test of the formulated muds was performed using API recommended practice for static filtration test at low temperature - low pressure (LTLP) condition. The results obtained showed that Detarium microcarpum and rice husk fluid loss volume and filter cake thickness were comparable with that of CMC from additive content of 10g, while Brachystegia eurycoma was comparable from additive content of 15g. Furthermore, the composite additive results indicated that Detarium microcarpum-rice husk at 95% Detarium microcarpum-5% rice husk performed better than Brachystegia eurycoma-rice husk of the same combination. Additionally, the fluid loss volume and filter cake thickness of Detarium microcarpum-rice husk additive were comparable with CMC from 10g content. Also, the results revealed that the fluid loss volume and filter cake thickness obtained from the locally sourced materials were within API specification for fluid loss control agents. The mud filter cake characteristics exhibited by these materials depicted that they have slippery, smooth and soft mud cakes; thus, the characteristics of a good mud cake that will prevent differential pipe sticking.