Case Study of Identifying and Minimizing Formation Damage in Tight Reservoirs Caused by Drilling Fluids in Abu Dhabi Onshore Operation Using Compatibility Coreflood Studies

2021 ◽  
Author(s):  
Raymond Saragi ◽  
Mohammad Husien ◽  
Dalia Salim Abdullah ◽  
Ryan McLaughlin ◽  
Ian Patey ◽  
...  
Keyword(s):  
Positive Impact ◽  
Abu Dhabi ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Hydrocarbon Recovery ◽  
Tight Reservoirs ◽  
Filtrate Loss ◽  
Drilling Muds ◽  
Loss Control

Abstract A study was carried out to examine formation damage mechanisms caused by drilling fluids in tight reservoirs in several onshore oil fields in Abu Dhabi. Three phases of compatibility corefloods were carried out to identify potential to improve hydrocarbon recovery and examine reformulated/alternate drilling muds and treatment fluids. Interpretation was aided by novel Nano-CT quantifications and visualisations. The first phase examined the current drilling muds and showed inconsistent filtrate loss control alongside high levels of permeability alteration. These alterations were caused by retention of drilling mud constituents in the near-wellbore and incomplete clean-up of drilling mud-cakes. Based upon these results, reformulated and alternate drilling muds were examined in Phase 2, and there was a positive impact upon both filtrate loss and permeability, although the Nano-CT quantifications and visualisations showed that drilling mud constituents were still having an impact upon permeability. Candidate treatment fluids were examined in Phase 3, with all having a positive impact and the best performance coming from 15% HCl and an enzyme-based treatment. The interpretative tools showed that these treatments had removed drilling mud-cakes, created wormholes, and bypassed the areas where constituents were retained. The compatibility corefloods on tight reservoir core, alongside high-resolution quantifications and visualisations, therefore identified damaging mechanisms, helped identify potential to improve hydrocarbon recovery, and identify treatment fluid options which could be used in the fields.

scholarly journals Modification of DS-01 Drilling Fluid to Reduce Formation Damage

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Winarto S. ◽  
Sugiatmo Kasmungin
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Laboratory Research ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Initial Flow ◽  
Lost Circulation ◽  
Negative Impacts ◽  
Drilling Muds

<em>In the process of drilling for oil and gas wells the use of appropriate drilling mud can reduce the negative impacts during ongoing drilling and post-drilling operations (production). In general, one of the drilling muds that are often used is conventional mud type with weighting agent barite, but the use of this type of mud often results in skin that is difficult to clean. Therefore in this laboratory research an experiment was carried out using a CaCO3 weigting agent called Mud DS-01. CaCO3 is widely used as a material for Lost Circulation Material so that it is expected that using CaCO3 mud will have little effect on formation damage or at least easily cleaned by acidizing. The aim of this research is to obtain a formula of mud with CaCO3 which at least gives formation damage. Laboratory experiments on this drilling mud using several mud samples adjusted to the property specifications of the mud program. Mud sample consists of 4, namely using super fine, fine, medium, and conventional CaCO3. First measuring mud properties in each sample then testing the filter cake breaker, testing the initial flow rate using 200 ml of distilled water and a 20 micron filter disk inserted in a 500 ml HPHT cell then assembled in a PPA jacket and injecting a pressure of 100 psi. The acidification test was then performed using 15% HCL and then pressured 100 psi for 3 hours to let the acid work to remove the cake attached to the filter disk (acidizing). Laboratory studies are expected which of these samples will minimize the formation damage caused by drilling fluids.</em>

scholarly journals Reuse of Flowback Water from Hydraulic Fracturing for Drilling Mud Preparation and Secondary Hydrocarbon Recovery

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5921
Author(s):  
Ewa Knapik ◽  
Katarzyna Chruszcz-Lipska ◽  
Łukasz Łukańko ◽  
Sławomir Wysocki
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Recovery ◽  
Drilling Mud ◽  
Hydrocarbon Recovery ◽  
Flowback Water ◽  
Beneficial Reuse ◽  
Drilling Operations ◽  
Secondary Oil Recovery ◽  
Drilling Muds ◽  
Coagulation And Filtration

Flowback water after completion of hydraulic fracturing is one of major waste streams generated during the lifespan of a well so its beneficial reuse is crucial. The application of treated flowback is not limited to stimulation processes but also may include drilling operations and secondary oil recovery. The flowback water used in this work is characterized by high salinity reaching up to ~295 g/L caused mainly by NaCl. The presence of suspended solids, mainly corrosion products, prompts the use of coagulation and filtration as treatment methods. Among tested coagulants the most effective one was the SAX18 (NaAlO2) commercial coagulant applied at concentration of 12 mL/L which reduces the water turbidity from over 400 FTU to 23 FTU. The applied treatment greatly reduces the concentration of scaling ions and so the concentration of SiO2 is reduced by 64%, Ba2+–66%, Fe2–36%, Mn2+–65%, SO42−–66%. The treated flowback fluid can be reused in surfactant flooding for enhanced oil recovery where achieves 7% higher displacing efficiency than fresh water. The drilling muds which were prepared using the untreated flowback water exhibit good rheological properties. The obtained results show that recycling of flowback water in future drilling and exploitation operations is technically feasible.

scholarly journals Investigation of Non-Linear Rheological Characteristics of Barite-Free Drilling Fluids

Fluids ◽  
2021 ◽  
Vol 6 (9) ◽  
pp. 327
Author(s):  
Ekaterina Leusheva ◽  
Nataliia Brovkina ◽  
Valentin Morenov
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Rheological Parameters ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Gas Wells ◽  
Oil And Gas Wells ◽  
Fluid Properties ◽  
Hydrolyzed Polyacrylamide ◽  
Drilling Muds

Drilling fluids play an important role in the construction of oil and gas wells. Furthermore, drilling of oil and gas wells at offshore fields is an even more complex task that requires application of specialized drilling muds, which are non-Newtonian and complex fluids. With regard to fluid properties, it is necessary to manage the equivalent circulation density because its high values can lead to fracture in the formation, loss of circulation and wellbore instability. Thus, rheology of the used drilling mud has a significant impact on the equivalent circulation density. The aim of the present research is to develop compositions of drilling muds with a low solids load based on salts of formate acid and improve their rheological parameters for wells with a narrow drilling fluid density range. Partially hydrolyzed polyacrylamide of different molecular weights was proposed as a replacement for hydrolized polyacrylamide. The experiment was conducted on a Fann rotary viscometer. The article presents experimentally obtained data of indicators such as plastic viscosity, yield point, nonlinearity index and consistency coefficient. Experimental data were analyzed by the method of approximation. Analysis is performed in order to determine the most suitable rheological model, which describes the investigated fluids’ flow with the least error.

scholarly journals Effect of anionic polyelectrolytes on the flow of activated sodium bentonite drilling mud

2018 ◽  
Vol 149 ◽  
pp. 01082
Author(s):  
Kaci Chalah ◽  
Abdelbaki Benmounah ◽  
Khaled Benyounes
Keyword(s):  
Yield Stress ◽  
Xanthan Gum ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Sodium Carboxymethylcellulose ◽  
Low Viscosity ◽  
Water Based ◽  
Different Types ◽  
Drilling Muds ◽  
Practical Recommendations

Bentonite is often used in water-based drilling fluids. The xanthan gum is widely used as to increase the viscosity of the bentonite suspension. For the stabilization of the drilled layers, we use filtrate reducers: sodium carboxymethylcellulose low viscosity and cellulose polyanionic low viscosity. The objective of this work is to explain the effect of the polymers on the rheological behavior of the 5% bentonite suspensions. These results will provide practical recommendations for the rational use of different types of additives in water-based drilling muds. Our work is based on rheological trials on a viscometer. The results obtained on the bentonite 5%-xanthane suspension show a rheofluidifying behavior with yield stress conform to the Herschel-bulckly modal. While increasing the concentration of filtrate reducer decreases the yield stress and reduces the viscosity. The effect of CMC LV is more pronounced than PAC L.

pH-Sensor Under Consideration for Multi-Sensor-Chip in Downhole Drilling Fluid Monitoring

2017 ◽  
Author(s):  
Jonathan Kühne ◽  
Frederic Güth ◽  
Heike Strauß ◽  
Yvonne Joseph ◽  
Pál Árki
Keyword(s):  
Optical Sensors ◽  
Drilling Fluid ◽  
Drill String ◽  
Glass Electrode ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Ph Sensing ◽  
Drilling Mud ◽  
Ph Sensors ◽  
Drilling Muds

Modern drill strings for the exploration of oil and gas are equipped with a variety of sensor carrying devices such as Measurement While Drilling (MWD), Logging While Drilling (LWD), and Formation Testing While Drilling (FTWD). These devices generate a large amount of downhole data, such as the orientation of the well, drilling parameters e.g. weight on bit and torque, and formation properties. Appropriate telemetry systems are included in the drill string to transfer relevant downhole data in real time to the surface. Other data is stored in memories downhole for subsequent evaluation. However, drilling fluid properties are still monitored at the surface and their behavior under borehole conditions is predicted with hydraulic models. Commercial solutions for a direct downhole measurement of various drilling fluid parameters are rare, though they would increase drilling process safety and the knowledge about the behavior of drilling fluids under real bottomhole conditions. The pH has a significant influence on the properties of water-based muds and plays a role in the chemistry of oil-based muds as the water cut in the emulsion increases. Commercial pH-sensing devices, such as the glass electrode, and optical sensors are not appropriate for the pH measurement under bottomhole conditions. Fragility, the insufficient degree of miniaturization, the low temperature and pressure resistance due to the liquid reference electrolyte, and phenomena such as the alkaline error are certain drawbacks of glass electrodes. Often optical sensors often will not capture the whole pH scale and require the medium to be at least slightly transparent for light. The usage of pH-sensors based on EIS (electrolyte-isolator-semiconductor) structures is a possible application of chemical sensors for drilling fluid monitoring under in situ borehole conditions. This paper presents results from a study on the behavior of an EIS structure as a pH sensitive electrode measured vs. a commercial Ag/AgCl reference electrode in comparison with a commercial glass electrode. EIS structures are capacitive pH sensors where the sensing layer is generally a metal oxide on a semiconductor substrate. Measurements in basic drilling muds were conducted under constant temperature and atmospheric pressure while the drilling mud was steadily stirred. The mud was titrated from alkaline to acidic conditions with hydrochloric acid and the pH was measured after potential equilibration at the electrodes. The results show a general feasibility for the usage of the proposed sensor. There are still certain challenges to be overcome in the development of a robust and reliable pH-sensing device for complex fluids, such as drilling muds under high pressure/high temperature (HP/HT) conditions.

scholarly journals Applications of Biodiesel in Drilling Fluids

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ashraf Ahmed ◽  
Salaheldin Elkatatny ◽  
Saad Al-Afnan
Keyword(s):  
Chemical Reactivity ◽  
Drilling Fluid ◽  
Chemical Properties ◽  
Temperature Stability ◽  
Lessons Learned ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Long Chain Fatty Acid ◽  
Drilling Muds ◽  
Physical And Chemical

Biodiesel, referred to as the monoalkyl ester of long-chain fatty acid ester that is synthesized by the complete transesterification of triglycerides, has captured the attention of drilling researchers attributing to its magnificent characteristics such as the high flash point, excellent lubricity, nontoxicity, high biodegradability, and abundant feedstock resources, which make it ecofriendly and technically and economically feasible for a sustainable drilling operation. There are several studies that reported and documented the usage of biodiesel in drilling fluids on laboratory and field scales. In this paper, the production and the key physical and chemical properties of biodiesel are thoroughly reviewed. Moreover, the applications of biodiesel in drilling muds either as base fluids or additives were comprehensively surveyed. The literature review revealed that the challenges of biodiesel applications in drilling mud systems are related to its chemical reactivity and adverse interactions with some additives, along with its performance deficiency at temperature above 120°C. Therefore, further investigation on temperature stability and additive compatibility is recommended. In addition, as a new approach, it is recommended to study the potentiality of using crude waste oils in drilling mud formulations. The lessons learned and recommendations stated in this paper will assist in enhancing the proved use of biodiesel and drilling fluid optimization.

scholarly journals Development of a Weighted Barite-Free Formate Drilling Mud for Well Construction under Complicated Conditions

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4457
Author(s):  
Valentin Morenov ◽  
Ekaterina Leusheva ◽  
Tianle Liu
Keyword(s):  
Alkali Metals ◽  
Oil And Gas ◽  
Solid Phase ◽  
Drilling Fluids ◽  
Formation Pressure ◽  
Drilling Mud ◽  
Organic Salts ◽  
Clay Rocks ◽  
Solids Content ◽  
Drilling Muds

Construction of oil and gas wells at offshore fields often involves high formation pressure and the presence of swellable clay rocks in the section. In addition, productivity preservation is also an important aspect. For this purpose, it is necessary to reduce the solids content of the drilling mud. The purpose of this work is to develop, improve, and study compositions of weighted drilling muds with low content of solids, on the basis of organic salts of alkali metals and polymers for the construction of wells prone to rock swelling and/or cavings, as well as drilling fluids for drilling-in the formation. In order to achieve the set goal the following is required: Analysis of existing drilling muds of higher density for drilling wells in unstable rock intervals and for drilling in the productive formation; analysis of experience in using drilling systems on the formic acid salts base and substantiation of requirements for flushing fluids during well construction; development and investigation of drilling mud compositions on the formate base; and the evaluation of inhibiting effect of systems containing organic salts, polymer reagents, and calcium carbonate on clay samples. The developed drilling mud is characterized by a high inhibiting ability that allows minimized mud-weighting by the natural solid phase. This reduces the volume of prepared mud and facilitates the regulation of its properties by reducing the dispersion of drilled cuttings; it eliminates problems related to hydration and the swelling of active clay rocks; and stabilizes unstable argillites prone to caving. The low solids content, low filtration rates, and inhibitory nature of the mud allows high stability of the rheological properties of the mud, and preserves oil and gas reservoir productivity under conditions of elevated formation pressure.

scholarly journals Dependence of the Equivalent Circulation Density of Formate Drilling Fluids on the Molecular Mass of the Polymer Reagent

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7639
Author(s):  
Ekaterina Leusheva ◽  
Valentin Morenov ◽  
Tianle Liu
Keyword(s):  
Molecular Weight ◽  
Formic Acid ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Technological Parameters ◽  
Gas Wells ◽  
Flow Rates ◽  
Hydrolyzed Polyacrylamide ◽  
Drilling Muds

Construction of offshore gas wells is characterized by increased requirements for both the technological process in general and the technological parameters of drilling fluids in particular. Parameters and properties of the used drilling muds must meet a large number of requirements. The main one is the preservation of the permeability of the reservoirs, in addition to the environmental and technological concerns. At the same time, pressures in the productive formation at offshore fields are often high; the anomaly coefficient is 1.2 and higher. The use of barite in such conditions can lead to contamination of the formation and a decrease in future well flow rates. In this regard, the development and study of the compositions for weighted drilling muds is necessary and relevant. The paper presents investigations on the development of such a composition based on salts of formic acid (formates) and evaluates the effect of the molecular weight of the polymer reagent (partially hydrolyzed polyacrylamide) on the equivalent circulation density of the drilling fluid. The result of the work is a formate-based high-density drilling mud with no barite added. Application of such a mud will preserve the permeability of the productive formation.

Lost-Circulation Control for Formation-Damage Prevention in Naturally Fractured Reservoir: Mathematical Model and Experimental Study

SPE Journal ◽  
2017 ◽  
Vol 22 (05) ◽  
pp. 1654-1670 ◽  
Author(s):  
Chengyuan Xu ◽  
Yili Kang ◽  
Lijun You ◽  
Zhenjiang You
Keyword(s):  
Mathematical Model ◽  
Laboratory Data ◽  
Fracture Propagation ◽  
Formation Damage ◽  
Fluid Loss ◽  
Fractured Reservoir ◽  
Geometrical Properties ◽  
Lost Circulation ◽  
Tight Reservoirs ◽  
Loss Control

Summary Drill-in fluid loss is the most important cause of formation damage during the drill-in process in fractured tight reservoirs. The addition of lost-circulation material (LCM) into drill-in fluid is the most popular technique for loss control. However, traditional LCM selection is mainly performed by use of the trial-and-error method because of the lack of mathematical models. The present work aims at filling this gap by developing a new mathematical model to characterize the performance of drill-in fluid-loss control by use of LCM during the drill-in process of fractured tight reservoirs. Plugging-zone strength and fracture-propagation pressure are the two main factors affecting drill-in fluid-loss control. The developed mathematical model consists of two submodels: the plugging-zone-strength model and the fracture-propagation-pressure model. Explicit formulae are obtained for LCM selection dependent on the proposed model to control drill-in fluid loss and prevent formation damage. Effects of LCM mechanical and geometrical properties on loss-control performance are analyzed for optimal fracture plugging and propagation control. Laboratory tests on loss-control effect by use of different types and concentrations of LCMs are performed. Different combinations of acid-soluble rigid particles, fibers, and elastic particles are tested to generate a synergy effect for drill-in fluid-loss control. The derived model is validated by laboratory data and successfully applied to the field case study in Sichuan Basin, China.

Influence of Drilling Muds on the Primary Chemosensory Neurons in Walking Legs of the Lobster, Homarus americanus

1981 ◽  
Vol 38 (3) ◽  
pp. 268-274 ◽  
Author(s):  
Charles D. Derby ◽  
Jelle Atema
Keyword(s):  
Feeding Behavior ◽  
Homarus Americanus ◽  
Normal Activity ◽  
Drilling Mud ◽  
Behavioral Deficits ◽  
Chemosensory Neurons ◽  
Petroleum Fractions ◽  
Food Odors ◽  
Normal Feeding ◽  
Drilling Muds

The effects of whole drilling muds on the normal activity of walking leg chemosensory neurons of the lobster, Homarus americanus, were examined using extracellular neurophysiological recording techniques. Exposure of legs for 3–5 min to 10 mg/L drilling mud suspended in seawater altered responses to food odors of 29% of the chemoreceptors examined (data pooled for the two drilling muds tested); similar exposure to 100 mg/L drilling mud resulted in interference with 44% of all receptors studied. The effects of both of these concentrations are statistically significant, although they are not different from each other. Interference was usually manifested as a marked reduction in the number of action potentials in a response. In one preparation, the exposure to drilling mud caused a change in the temporal pattern of the spikes without affecting the total number of spikes. Other chemosensory neurons were excited by 10 mg/L drilling mud itself. However, not all chemoreceptors are inhibited by these drilling muds since responses to feeding stimuli were recorded from the legs of lobsters that had been exposed to drilling mud for 4–8 d before the neurophysiological experiments.Antennular and leg chemoreceptors are important in eliciting normal feeding behavior in lobsters. Although behavioral assays have demonstrated that feeding behavior is altered following exposure to drilling muds and petroleum fractions, there is no conclusive proof for a causal relationship between chemoreceptor interference and behavioral deficits. The two techniques complement each other as pollution detection assays, perhaps reflecting a common interference mechanism.Key words: chemoreception, drilling mud, feeding behavior, lobster, pollution, neurophysiology

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