bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Formulation for High Temperature Acidizing Treatment Using Sustainably Sourced Additives
Authors: Li Jiang , Suzanne Stewart , Jonathan Abbott 
Published: March 2023

Abstract
Calcite reservoir represents a significant portion of hydrocarbon resources in subterranean formations. Most mineral acid based stimulation treatments to carbonate and sandstone reservoirs under high temperature encounter a fundamental problem, i.e., the etching rates are too fast and the treatment fluid is fully spent before it has the opportunity to be transported deeper into the formation, resulting in ineffective matrix treatment. The materials and compositions described herein are able to modulate the critical etching rate so that it can penetrate deep into the formation, generating a more extensive wormholing network required for high production yield.
This paper intends to report a new formulation that is capable of modulating the reaction rates between mineral acids and carbonaceous materials that are associated with important subterranean treatments including matrix acidizing, acid fracturing and filter cake dissolution. The formulation is composed of two environmentally friendly and sustainable materials; one polymeric with direct effect on acid reaction rate modulation by controlling the mass transfer rate of acidic proton at a given temperature in a tunable manner, and the other, micro fibrous bundles functioning to keep the reaction products from aggregating.
A full range of laboratory based qualification tests will be presented to demonstrate the principles of the functional additives in the new formulation. At ambient temperature, it was demonstrated that the reaction rates with calcium carbonate powder and Indiana Limestone can be modulated by using different dosages of the formulation. In addition, the typical acid fume in the headspace is effectively suppressed in the presence of the formulation. Furthermore, the formulation is compatible with commonly used corrosion inhibitor over extended time, and the corrosion inhibition performance using common metallurgies in the presence of an appropriate dosage of corrosion inhibitor between 250°F and 320°F over 6-12 hours duration met the oilfield performance requirement. The proof of concept coreflooding tests using Indiana Limestone and Bonne Terre Dolomite cores have identified domains of injection rates that exhibiting high efficacy of core penetration with a minimum of acidizing agent required. In addition, corrosion inhibition tests at temperatures ranging from 250°F to 320°F, duration from 6 to 12 hours, and acid concentrations at 15% and 20% HCl equivalent.
The new acid formulation is anticipated to bring major advantages to acid stimulation jobs including: (a) deployablility to higher temperature domains that are otherwise beyond the reach of raw mineral acids; (b) deeper wormholes to enhanced well productivity; and (c) cost-effectiveness because of its remarkable breakthrough efficiency it exerts in carbonate reservoir compared to larger volumes of conventional acidizing systems that are needed for similar treatments.
Establishing Critical Gas Velocities for Liquid Loading in Deviated Gas Wells
Authors: Ejim Chidirim 
Published: March 2023

Abstract
Severe liquid loading in wells producing from some wet gas reservoirs, results in the well being unable to transport fluids to surface. In field applications, liquid loading is known to be more pronounced in deviated wells than in vertical wells. This study highlights a methodology to estimate the critical velocities for liquid loading in inclined gas wells. Knowledge and use of the technique is of importance to production engineers and stakeholders of a gas asset.
Test data from a 3-inch diameter line with inclination from vertical to near horizontal was obtained from open literature. For each deviation angle, and based on the test conditions, a correlation for liquid holdup in inclined wells was used to determine the void fraction at the region of interest. The corresponding maximum and average film thicknesses, as well as the interfacial friction factor were determined. The principle of momentum conservation for a deviated tubing was applied and the superficial critical gas velocities for liquid loading were estimated. These estimated velocities were compared to those obtained from the test data.
For the different superficial liquid velocities investigated, the estimated critical gas velocities increased with increasing deviation from vertical. The maximum critical velocity was reached when the deviation angle was about 40° to 50° from vertical. Beyond this point, the critical gas velocity decreased with increasing deviation angle from vertical up to the near-horizontal inclination. The results also showed that the gas critical velocity increased with increasing liquid superficial velocity. The overall trend of the critical velocity variation was similar to the trend in the actual test data obtained from open literature. The range of estimated critical gas velocities varied from about 9 m/s to about 35 m/s, with overall Root Mean Square Errors between 3.3 m/s and 6 m/s. In conclusion, results from this methodology was able to give a first-hand estimate of critical superficial velocities for inclined gas wells.
This work presents a methodology to estimate critical gas velocities for inclined gas wells. This knowledge is important for field engineers and asset managers in the planning and production phases of gas wells. The benefits include optimizing the gas completion hardware during design, and maximizing gas flow rates during production operation. Overall, this increases the economic bottom-line for the field operator.
First Successful 16 X 13.375-in. Casing-While-Drilling Operation in Kuwait Saves 27 Rig Days and Reduces Well Delivery Time
Authors: Muqeem Saleh , Al-Mulaifi Mohammed , Al-Assil Yasser , Sekhri Anish , Sulaiman Mai Yacoub , Shekhar Chandra , Abdelrahman Ibrahim , Abdulkareem Talal , Homi Jokhi Ayomarz , El Kady Mahmoud , Al Saad Naser , Al Muzaini Shahad , Mataqi Fatemah , Al Harbi Saad , Al Kanderi Naser , Herrera Delimar , Halma Jeremy , Ibrahim Sameh , James Biju 
Published: March 2023

Abstract
Drilling the 16-in. section in Minagish field wells in western Kuwait is among the most challenging well sections. Challenges include drilling through severe loss conditions, destabilized shale, and deteriorating hole conditions. These conditions can result in hole collapse or lost in hole of the drill string that requires sidetracking. The objective of project presented in this paper was to develop an engineered solution to drill through the difficult zones, lessen nonproductive time, and reduce the total well cost.
The solution proposed was to use casing-while-drilling technology with a drillable bit and drill through the fractured dolomitic limestone and sandstone formation while simultaneously setting casing. The drillable casing-while-drilling bit was specifically designed and engineered to conform to the formations in the field. The drillable casing-while-drilling bit is manufactured with a material that can be drilled out with either conventional roller cone or fixed cutter bits. A plastering process was used, which smears the cuttings generated by drilling against the borehole wall, seals the pores or fractures in the formation, and helps reduce fluid losses while maintaining well integrity.
The first successful 16 × 13.375-in. casing-while-drilling job in Minagish field reduced well delivery time for the operator and saved 27 rig days with substantial savings in the total well cost. The section was drilled successfully while encountering total mud losses through fractured dolomitic limestone and sandstone formations. Continued drilling managed to reduce losses with 30 to 50% returns and reached the target depth. Preventing the risk of losing the bottomhole assembly in the hole and alleviating the use of multiple cement plugs saved additional cost for loss-cure plugs to heal the loss-prone formations. After reaching the target depth, cementing, pressure testing of the casing, and drillout of the drillable casing-while-drilling bit using a rerun fixed cutter bit were performed successfully.
On an average, eight wells are drilled per year in this field. With the successful implementation and the savings obtained by using this casing-while-drilling technology in the first test well, there is the potential for substantial annual cost savings, help the operator deliver wells in less time, and eventually increase production by increasing the number of wells drilled per year.
Deployment of an Eccentric Borehole Conditioning Tool Yields Significant Drilling Efficiency Improvements
Authors: Bailey Michael James , Roberts Sion Llywelyn , Suleiman Ahmed , Ismail Ahmed 
Published: March 2023

Abstract
Wellbore conditioning has become prominent in recent years as operators strive to reduce flat time costs. This paper examines how an eccentric wellbore conditioning tool (WCT) improves drilling performance and reduces flat time in challenging sections. Torque and drag are common challenges in extended laterals, with micro-doglegs and ledges being major culprits, especially in hard carbonate formations. The performance of the WCT is benchmarked in terms of flat time components: trip speed, system torque, rate of penetration (ROP), casing operations, and on-bottom performance. The paper also scrutinizes the allowable parameter envelope for wells drilled with and without the WCT.
Laboratory testing was conducted to observe the behavior and effects of the eccentric WCT when confronted by the major wellbore conditioning challenges. Following these initial laboratory tests, a proprietary software program was created to determine the WCT's ideal bottom hole assembly (BHA) placement for field trials. Several field trials were conducted to validate the placement software's accuracy as well as the key benefits achieved by the WCT.
Development testing has proven that the WCT's capabilities reliably improve wellbore quality and reduce overall torque and drag. Also, a proprietary software program confirmed the most effective WCT placement. Overall, there was a net flat time reduction and a marked improvement in ROP—up to 35% when directly compared with and without the WCT. Reduced system torque and less stress on downhole tools enable a wider and, more importantly, higher drilling parameter window.
A new generation of eccentric WCTs has been introduced to solve a legacy drilling pain. Poor wellbore conditioning contributes to significant flat time costs for operators worldwide. A proven, effective solution has been long overdue; however, the WCT has shown to be a cost-effective tool, improving flat time and drilling performance. The benchmarking and exploration of drilling performance and reduced flat time provided by wellbore conditioning tools will allow others to exploit lessons learned and recapture drilling efficiency.
Tailored Cement Systems with Enhanced Mechanical Properties Designed to Eliminate Sustained Casing Pressure in Development Wells
Authors: Chekuri Pushkara Varma , Singhal Ashish , Kaura Sheraya , Dange Mikhil , Kumar Animesh , Singh Swarnima 
Published: March 2023

Abstract

Objectives/Scope
Oil and gas wells in the Barmer fields (Rajasthan, India) typically require a timeframe of five to seven days for well completion. The cementing process includes a wide range of challenges, including low fracture gradients, lost circulation, and sustained casing pressure (SCP). Because the baseline challenges were identified from cementing through completion phases, the target was to design a tailored, gas-tight, resilient, lightweight cement system to address wellbore integrity issues. The modelled simulations showed the rheological behaviour, equivalent circulating density (ECD), pumping rates, and maximum surface pressure, whereas the 3D model predicted the sweep efficiency of the pumped fluids. Elastomeric materials were incorporated into the designs to counter the stresses induced during well activities. Advanced laboratory testing was performed to ensure that these lightweight slurries met the requirements to address multiple issues by exhibiting suitable mechanical properties (based on finite element analysis (FEA) simulation output), gas-tight behaviour, and lost circulation curing capabilities. Three stable cement slurries were designed with the available set of additives to simplify operations.
Elastomeric additives altered the mechanical properties of the set-cement sheath to provide greater resilience than conventional cement. More than 22 wells were cemented with a varied range of densities that were designed/modified with the available chemical additives, based on the severity of the depleted reservoir zones. To ensure completion of the full process (ranging from design to completion of the cement job), multiple verifications/checks were implemented. Quality control played an important part, and all new bulk blended batches were tested for mechanical properties. The wide range of densities and sensitivity tests of the cement system assured reliable implementation.
The successful design and cemented completion resulted in the reduction/elimination of sustained casing pressure. SCP, which may have been a safety hazard, influences production rates and, in the worst case, could compromise the structural integrity of the well. Results indicated that more than 90% success was achieved in the targeted segment of the field, in terms of SCP in the B-annulus (after cementing and perforation of the wells) where the values were well below their maximum allowable limits. The returns to surface, excellent cement bond logs, microseismogram, circumferential visualization, and zonal isolation under lost circulation conditions further justified the performance of enhanced slurry designs.
Geomechanical Analyses of Hydraulic Fracturing Efficiency and Challenges in a Tight Clastic Reservoir: Experiences Over Years
Authors: Vossen Johannes , El Sherbeny Wael , Perumalla Satya , Hamid Osman , Arshad Waheed 
Published: March 2023

Abstract
Hydraulic fracturing experiences were gathered over the years, from a tight sandstone reservoir of Late Carboniferous to Early Permian origin to find the root causes for the persisting challenges of high formation breakdown pressures and low fluid injectivity. It was soon realized that a single root cause could not account for these challenges. Instead, a multitude of reasons acting at the same time during the injecting sequence of that particular fracturing stage could easily be responsible, and no single re-occurring pattern would explicitly repeat in the consequent stages under similar conditions. It was found that the known complex nature of the depositional environment of the targeted formation played an important role, but the overall hydraulic fracturing mechanics played an equally critical part in the success of the fracturing attempt. Having realized this complexity in deciphering hydraulic fracturing performances it became imminent that not only the fracturing execution had to be refined, but all the preceding activities from drilling operations, to well placement, to wellbore preparation, to the choice of completion equipment and its deployment. These operations critically influenced the near wellbore region. The drilling fluid properties, wellbore hydraulics, well trajectory, the wellbore clean-out procedures, and hole quality were important contributors in the geo-mechanics domain coupled with the impact of the geological setting. Thus, a workflow was developed to analyze and rationalize the root causes for the injectivity challenges with the goal of optimizing every well construction step that would enhance hydraulic fracturing and ultimately deliver optimum well productivity.
Maintaining Hydraulic Fracture Conductivity Under High Stresses Through Consolidation with DAP
Authors: Desouky Mahmoud H. , Aljawad Murtada S. , AlTammar Murtadha J. , Alruwaili Khalid M. 
Published: March 2023

Abstract
Acid fracturing creates conductive fractures in carbonate reservoirs through acid-rock dissolution. However, over-etching or stimulating weak carbonate formation could result in a fast decline of fracture conductivity. In addition, most models in the literature showed that rock strength has an exponential impact on fracture conductivity. In this work, experiments were conducted to mitigate this problem through rock strengthening with diammonium phosphate (DAP).
Different fracture surfaces were tested using the ACM-3000 acid fracture conductivity system to compare the conductivity of intact samples with the treated ones. The fracture conductivity of 4 pairs of weak Austin chalk samples (7in × 1.34in × 3in) with flat surfaces was evaluated by flowing nitrogen gas (200-350 cc/ min) at increasing stresses up to 1,500 psi. Half of the samples were kept intact to represent the control group to which treated samples were compared. The treatment consists of saturating vacuumed chalk samples with 1M DAP for 72 hrs at pressure and temperature of 1,000 psi and 75°C, respectively. In addition, the surface hardness of the samples was measured pre-and post-treatment, and conductivity measurements were performed to evaluate the treatment effect on the samples.
The chalk samples used in this study are naturally weak with low average surface hardness (i.e., 3 GPa compared to 15 GPa for Indiana limestone). However, The DAP solution can remarkably boost the surface hardness of soft chalk, increasing it by nearly double its original value. The chalk hardness increase reduced the normal deformation and increased the yield stress of the treated samples. The untreated sample exhibited lower endurance to loading and developed cracks at lower stresses. Also, the results showed that the normalized conductivity of the treated flat samples is at least double the untreated ones. The chemical treatment makes the chalk stiffer with less deformation when stressed, which leads to enhanced conductivity at higher stress.
In this paper, an additional stage is suggested in acid fracturing to harden the surface of carbonate rocks chemically after acid injection. Successful application of such treatment in the field can extend fracture life and substantially reduce the need for re-fracking jobs.
Multifunctional Cementing Additives, A Way to Improve Rig Time Saving and Annulus Fluid/Gas Migration During Cement Placement
Authors: Frittella Francesco , Santos Auribel Dos , Jallad Hussam , Hartanti Stephanie , Sundblom Andreas 
Published: March 2023

Abstract
Controlling gas migration in the annular space during cement placement involves several challenges; especially in deep wells where temperature contrast leads to longer wait-on-cement (WOC) time, widening the window where fluids can migrate. Such extended setting is caused by the lower temperature in upper sections which impacts compressive strength build-up while also leads to higher rig time costs. In this paper, the authors focused on key aspects of slurry design to minimize these problems.
Among the factors that contribute to the invasion and migration of gas and other fluids into the annular space, are insufficient hydrostatic pressure, poor slurry design, inefficient mud removal, problems during cement hydration, or defective cement-formation-casing bonding. For this study, an experimental method was followed to evaluate specific additives and their impact in gas control performance. Different slurry formulations were evaluated at a temperature range between 50°C and 110°C (120°F -230°F) while pressure kept at 5300 psi to minimize variables.
The laboratory evaluation included tests for determining thickening time, rheology, compressive strength, fluid loss and gas migration. The slurry design involved the use of a novel retarder based on synthetic polymer with carboxylic acid functionality as well as a colloidal silica dispersion. The results showed that the selected additives allowed the slurries to achieve the targeted thickening time with a right-angle set, a short transition time and quick build up in compressive strength. In addition, the migration tests indicated excellent gas control under evaluated conditions. The studied additives performed well individually and even better combined, with a synergistic effect when preventing gas migration and accelerating compressive strength build-up.
The additives evaluated showed multifunctional attributes that are beneficial not only to prevent gas migration and retard slurry setting, but also to accelerate compressive strength, a cement feature which allows significant savings in rig time costs.
Advanced Hole Cleaning in Horizontal Wells: Experimental Investigation Supported by a Downhole Clamp-On Tool
Authors: Skenderija Jelena , Koulidis Alexis , Sanchez Domingo Lattanzi , Ahmed Shehab 
Published: March 2023

Abstract
Up to 80% of stuck pipe events are hole cleaning related in the case of high-angle wells. Therefore, significant attention should be given to understanding hole cleaning as it is crucial to restricting stuck pipe-related non-productive time (NPT). In order to optimize hole cleaning efficiency, the fundamental objective of the proposed paper is to experimentally investigate cuttings transport supported by a downhole clamp-on tool.
This work approaches existing challenges by designing and building a custom flow loop that recreates the drilling environment of horizontal wells. The study provides additional steps and new ideas in developing a reliable experimental setup for a proper hole cleaning investigation. Accordingly, the process includes comprehensive dimensional analysis, detailed design, and building a desired experimental flow loop setup. A unique mechanical design allows pipe rotation while achieving a closed-loop system. A clamp-on tool assists in agitating the cuttings to reduce accumulation at the bottom of the borehole. Experimental performance with various cuttings compares scenarios with and without pipe rotation.
Among the key factors influencing cuttings transport in horizontal wells are drill pipe rotation (RPM), flow rate (Q), mud rheology, cuttings size, flow regime, and penetration rate (ROP). This research focuses on the mechanical removal of solid cuttings. Experimental work emphasizes cuttings' behavior showing different patterns for their movement in deviated wells by utilizing image processing. Drillstring rotation proves to be a crucial factor for efficient hole cleaning. The specific shape and dimensions of the clamp- on tool affect the efficiency of the hole cleaning process and impact the distance covered by the agitated cuttings downstream of the tool. The concept of the tool depends on blades that agitate cuttings as it rotates. Optimum tool design considers the physical properties of the fluid and the cuttings. The results show that as the tool agitates cuttings and moves them into the higher velocity region, the cuttings advance with the flow, which improves cuttings transport and reduces bedding formation. Assuming low flow rates, tool application increased average particle velocity within the tool more than four times (372%) and twice after the tool. In addition, differential pressure (Δp) shows a significant decrease while the tool operates, indicating improvement in hole cleaning.
Lab-scaled flow loop development aims to simulate drilling conditions with drillpipe rotation and different downhole clamp-on tool geometries. The results show different flow patterns from experimental observations of liquid-particles flow in the horizontal wellbore, assisted by the proposed downhole clamp- on tool. The innovative tool design is a promising step in reducing hole cleaning issues with mechanical- assisted tools.