bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unique Synergistic Surfactant Mixture to Match Ultralow Interfacial Tension with Solubility at High Temperature and High Salinity
Authors: Herman George , Lichterfeld-Weber Nicole , Bittner Christian 
Published: October 2022

Abstract
Chemical enhanced oil recovery offers the huge benefit to reduce the carbon footprint in oil production. Mature oil fields with existing infrastructure can be turned into fields with higher productivity. Thereby, costly exploration of new fields can be avoided. The rejuvenation of mature oil fields can be achieved by surfactant flooding. Well-designed surfactants can reduce the tension between crude oil and water to ultralow values and thereby mobilize physically trapped oil. With respect to fields of high salinity and elevated temperature, it is particularly challenging to match the reduction of interfacial tension with the surfactant solubility as well as the chemical stability. In this paper, the solubility of surfactants in model reservoir brine (rich in calcium and magnesium ions) at elevated temperature was evaluated. The capability of surfactants to reduce interfacial tension between light crude oil and model reservoir brine was tested by phase behavior tests as well as by spinning-drop experiments. The thermal stability of stored surfactant solutions was analyzed by use of high-performance liquid chromatography (HPLC). The focus of the investigations was a temperature above 100°C and salinities of at least 100,000 ppm TDS for fields with light crude oils. Alkyl ether carboxylates are chemically very stable and offer a good potential to reduce interfacial tension. However, they usually lack sufficient solubility. In contrast, cationic surfactants are well soluble under such harsh conditions. However, they typically lack chemical stability and sufficient potential to reduce the interfacial tension. By taking the typical degradation pathways of cationic surfactants into consideration, it was possible to identify a cationic surfactant that is stable under harsh conditions. A well-designed formulation of the alkyl ether carboxylate with the cationic surfactant allows to match reduction of interfacial tension with solubility. Several other surfactant classes and their combinations were evaluated, but they were not able provide similar performance. This study reveals a unique synergistic surfactant mixture, which provides ultralow interfacial tensions against light crude oil at elevated temperature of 125°C and at high salinity 139,000 ppm TDS. In addition, the surfactant mixture is soluble and chemically stable under such harsh conditions.
A Success Story of the First Miscible CO2 WAG Miscible WAG Pilots in a Giant Carbonate Reservoir in Abu Dhabi
Authors: Mabkhout AlSeiari Reem Ali , Bhushan Yatindra , Igogo Arit , Singh Manjit Kumar , Marzooqi Saeeda Al , Al Hammadi Shareefa Ahmed , Khan Sara Hasrat , Mohamed Moza Abdelrahman , Brodie James , Tenaiji Aamna Al , Al Ali Mona Yousif , Al Keebali Aaesha Khalfan , Masalmeh Shehadeh 
Published: October 2022

Abstract
The key objective of the CO2 WAG Pilots is to confirm improved sweep and to enhance oil recovery under CO2 WAG relative to water flooding. Two CO2 WAG Pilots are in progress in a giant Abu Dhabi Oil Reservoir. Each pilot has one horizontal producer and two horizontal injectors along with two vertical pilot observers. A detailed monitoring plan was designed and implemented to monitor pilots’ performance and track CO2 breakthrough and flow path. Injectivity of both water and CO2 was determined in the WAG cycles to investigate any loss of injectivity.
The producers are being tested daily for oil rate, water cut, GOR using multi-phase flow parameters (MPFM) while portable test separators are used every quarter to validate these measurements. PVT analysis of produced fluids are being carried out on samples from portable test separators and MPFM sampling point to monitor CO2 content.
Different gas and water tracers have been injected to trace the movement and breakthrough of injected fluids into the pilot producers. Carbon and oxygen-isotope analysis for produced and injected CO2 gas is also carried out to monitor CO2 breakthrough.
RST logs in the observers demonstrate good sweep across different layers of the reservoir and show that WAG is providing mobility control to CO2. Several data sources were analyzed to determine CO2 breakthrough time and the CO2 flow path. Analysis of CO2 in produced gas has determined the timing of CO2 breakthrough. This is supported by the isotopic analysis of injected and produced CO2 in pilot producers and near-by producers. The tracer analysis results unambiguously identify the source of the produced CO2. Injectivity analysis of both CO2 and water showed injectivity of CO2 was either the same or higher than water injectivity. Moreover, no loss of injectivity was observed between WAG cycles. The pilot has been operated successfully without HSE issues since 2016. Corrosion logs are acquired within the extensive monitoring program along with inhibitor injection to avoid any Asphalting deposition.
The paper discusses the performance of the first multi-well CO2-WAG pilots in a giant onshore reservoir in Abu Dhabi which is used to de-risk multiple CO2 WAG full field projects in ADNOC reservoirs. It also highlights the importance of the different reservoir monitoring tools for improved understanding of the pilots which will be used as a basis for implementing CO2 WAG for the full area development.
CO2-GOGD Subsurface Analysis in Fractured Carbonate in the Sultanate of Oman
Authors: Bos Robert , Mahruqi Dawood 
Published: October 2022

Abstract
The North Oman "A" Field is a giant fractured carbonate reservoir, that has been in production for more than 50 years. In recent decades, the predominant production scheme has been via Gas Oil Gravity Drainage (GOGD). In this scheme, hydrocarbon gas is injected into the high permeability fractures to allow for oil production from the low permeability matrix. In this paper we will study the option of replacing the hydrocarbon injection gas by sub-critical CO2 gas. This would have the advantage of storing CO2 in the matrix while making more hydrocarbon gas available for sales.
For the CO2 injection to be successful, the CO2 that is injected into the high permeability fractures needs to move into the low permeability matrix rock, even though there is no forcing viscous drive mechanism.
The mechanisms by which the CO2 can go into the matrix are:
Gas-Oil gravity drainage (CO2 gas in fractures is pulled into matrix to replace produced oil) Gas-Gas gravity drainage (CO2 gas in fracture has higher density than hydrocarbon gas in the matrix) Diffusion (Differences in concentration differences lead to CO2 moving into matrix).
In this paper we will present both analytical models and numerical modeling that show the relative contribution of each of these mechanisms.
In term of relative contribution, both analytical and numerical modeling shows that Gas-Gas gravity drainage is the most effective method from transferring denser CO2 gas to the matrix, followed by gas-oil gravity drainage. Diffusion only provides a small contribution.
In absolute terms, modeling results indicate that significant volumes of CO2 and commercially significant volumes of hydrocarbon gas can be recovered from the reservoir.
Overall, our assessment is that from a subsurface perspective, switching injection gas in GOGD from hydrocarbon gas to CO2 is attractive from both a commercial and an environmental perspective.
The novel contribution in this paper is that we present a subsurface analysis of a switch from hydrocarbon gas to CO2 in GOGD developments. This analysis is relevant because it provides a way to store CO2 while also providing extra sales gas.
Foam-Oil Displacements in Porous Media: Insights from Three-Phase Fractional-Flow Theory
Authors: Tang Jinyu , Castaneda Pablo , Marchesin Dan , Rossen William R. 
Published: October 2022

Abstract
Foam is remarkably effective in the mobility control of gas injection for enhanced oil recovery (EOR) processes and CO2 sequestration. Our goal is to better understand immiscible three-phase foam displacement with oil in porous media. In particular, we investigate (i) the displacement as a function of initial (I) and injection (J) conditions and (ii) the effect of improved foam tolerance to oil on the displacement and propagation of foam and oil banks.
We apply three-phase fractional-flow theory combined with the wave-curve method (WCM) to find the analytical solutions for foam-oil displacements. An n-dimensional Riemann problem solver is used to solve analytically for the composition path for any combination of J and I on the ternary phase diagram and for velocities of the saturations along the path. We then translate the saturations and associated velocities along a displacement path to saturation distributions as a function of time and space.
Physical insights are derived from the analytical solutions on two key aspects: the dependence of the displacement on combinations of J and I and the effects of improved oil-tolerance of the surfactant formulation on composition paths, foam-bank propagation and oil displacement. The foam-oil displacement paths are determined for four scenarios, with representative combinations of J and I that each sustains or kills foam. Only an injection condition J that provides stable foam in the presence of oil yields a desirable displacement path, featuring low-mobility fluids upstream displacing high-mobility fluids downstream. Enhancing foam tolerance to oil, e.g. by improving surfactant formulations, accelerates foam-bank propagation and oil production, and also increases oil recovery. Also, we find a contradiction between analytical and numerical solutions. In analytical solutions, oil saturation (So) in the oil bank is never greater than the upper-limiting oil saturation for stable foam (fmoil in our model). Nevertheless, in numerical simulations, So may exceed the oil saturation that kills foam in the oil bank ahead of the foam region, reflecting a numerical artifact. This contradiction between the two may arise from the calculation of pressure and pressure gradient using neighboring grid blocks in a numerical simulation.
The analytical solutions we present can be a valuable reference for laboratory investigation and field design of foam for gas mobility control in the presence of oil. More significantly, the analytical solutions, which are free of numerical artifacts, can be used as a benchmark to calibrate numerical simulators for simulating foam EOR and CO2 storage processes.
Embedding Physics and Data Driven Models for Smart Production Optimization. Field Examples
Authors: Mata Carlos , Badmaev Dorzhi , Saputelli Luigi , Mohan Richard , Rubio Erismar , Al Shehhi Maha , Salimov Rail , Eldjabri Mamar 
Published: October 2022

Abstract
The process of short-term water and gas flood optimization attempts to increase short term profit, while maximizing long term net present value (NPV) of the field. The characteristics of each production system would dictate how this process is achieved. Fields where the available producer well potential is significantly larger than the production quota could have infinite possible scenarios of production and injection well settings that would satisfy the field and reservoir production targets. But which of these scenarios maximize the long term NPV?
This paper explains the framework being implemented in ADNOC to streamline the optimization workflow, which runs both physics and data driven models, honours all constraints, and covers the associated processes from model maintenance, to calculation, execution, and monitoring. The workflows are orchestrated with a series of in-house interconnected digital solutions. This framework has been implemented in 5 production systems undergoing pattern injection of water, gas, and CO2. The associated digital solutions are well adopted by the asset teams.
Ability to optimize production and injection together has allowed the asset to focus on increasing injection capacity as the pattern, sector, and reservoir voidage constraints were identified to be the main constraint to production deliverability. The optimization scenario management and associated workflows have shown to deliver a gain of 1-3% of production by synchronizing the reservoir management process with the production operations business rhythm. The solutions have delivered so far more than 150 MM$ in value.
Test Protocol for Corrosion Resistant Alloys and Application to Material Selection for Ultra Sour Reservoir Containing Elemental Sulphur, in Continuation of SPE-203337-MS
Authors: Andres Bogdan , Vengan Chandrasekar , Mizukami Akio 
Published: October 2022

Abstract
Building upon the work detailed inSPE-203337-MS, the present work reports test results for the G3 alloy beyond the 4D limits defined by ISO 15156-3:2015/ NACE MR0175.
Corrosion of Oil Country Tubular Goods (OCTG) is a traditional concern in the Oil and Gas industry, as it represents a major component of well integrity management. Various corrosion mechanisms may affect the performance of materials in downhole applications, especially in corrosive environments containing large amounts of H2S, CO2, and Chlorides. In high sour environments, elemental Sulphur may also be present, in which case, it will act as a strong oxidizer, affecting the performance of the material selected.
In this paper, a test methodology was developed to select a techno economical fit for purpose material for application in the development of a Ultra Sour Reservoir Containing Elemental Sulphur. This methodology consisted in evaluation of the SCC (Stress Corrosion Cracking) behavior of Corrosion Resistant Alloys (CRA) of group 4D, as per ISO15156-3/ NACE MR0175-3, at the border between 4D and 4E environmental limits including the simultaneous presence of dissolved and elemental Sulphur in the fluid.
A testing set-up was developed to ensure the contact of elemental S with the material to ensure the strong oxidizing reaction at the surface of the material.
The behavior of the materials was assessed by Slow Strain rate testing (SSRT), C-Ring Sulphide stress cracking and Crevice corrosion test, conducted on UNS N06985.
CRAs have a greater CAPEX due to the content of costly chemical elements: Chromium, Nickel, Molybdenum, etc. However, they may be cost effective in a life cycle cost analysis by preventing workovers, assuring a higher HSE and well integrity level.
Solution for a Challenging Narrow Margin Deepwater Drilling Conditions - A Case Study from Lebanon
Authors: Martinez Jose Antonio , Kamel Mina Tawfik , Galiakbarov Dmitry , Bruce Stephen John 
Published: October 2022

Abstract
The requirements for offshore drilling continue to evolve to meet the needs of the industry, new technologies and drilling practices need to be adopted to accommodate these increasingly challenging environments. These new environments present challenges that include, but are not limited to, hole cleaning, wellbore stability, narrow margin drilling, and drilling fluid system stability over a wide range of temperatures. A high degree of planning and preparation is required in order to execute these wells, which will reduce any chance for a nonproductive time and deliver expected return on investment of the project. The need for a drilling fluid system that is designed to drill these challenging wells, is crucial to ensure the success of a project.
The well presented in this paper was the first well drilled in Lebanon and emphasizes the benefits of a low equivalent circulating density (ECD) impact drilling fluid when utilized in a deep-water environment. During the drilling phase of the project, the fluid was able to meet the demands of the operation by providing a low ECD while dealing with a range of temperature gradients that are associated with deep-water environments. The drilling fluid's unique performance ensured that any relevant nonproductive time events were mitigated and ensured the final delivery of the well. In addition, the fluid was able to meet these challenges with no additional treatment or modifications to the original planned fluid parameters for the project.
The low-impact, non-aqueous drilling fluid (LDIF) provided shear-thinning properties, flat rheological profile and non-progressive rapid-set/easy break gels. The fluid system benefited from a unique design that allowed the use of high yielding organophilic clay while utilizing an industry established low viscosity base oil. The synergy of the drilling fluid system when tailored to the base oil with kinematic viscosity as low as 1.7 cSt was able to provide rheological properties commonly associated to a clay-free non-aqueous base drilling fluid. The drilling fluid was able to provide a rheology that delivered a flat profile over the operating temperature range, while facilitating control of the ECD through the well. This operational experience shows how the choice of a proper fluid system together with a proper base fluid can ensure the unique challenges for the industry today can be successfully met.
Embedded Force Sensing at the Cutter
Authors: Koulidis Alexis , Zhan Guodong , Ahmed Shehab 
Published: October 2022

Abstract
Cutting and friction forces have been widely studied for PDC bits. Rock/bit interaction models are currently verified with a single cutter experiment and the utilization of multi-axis load cells. This paper aims to demonstrate an innovative method that experimentally validates the embedded cutter sensing on a laboratory scaled-drill bit to measure the forces acting on a single cutter.
A unique two-cutter drill bit design allows the integration of a sensor measuring the applied force on a cutter while drilling. A fully instrumented mini-rig is a key criterion to recreate the drilling environment. Control of the system and data analysis are performed while drilling, allowing continuous assessment of the drilled formations. Experiments are performed with new and worn cutters to independently evaluate the cutting and frictional components of the total measured force and compare them to the literature models. The high-frequency measurements at the cutter downscale the understanding that industry has on the bit-rock interaction and bring it to the cutter scale.
The effective cutting area changes dynamically depending on the position of the cutters in three dimensions and axial speed. The architecture of the mini-rig control system allows accurate control of depth of cut and interactive graphs of the acquired data. The cutter sensing enables spatial monitoring distribution of the cutting forces over the face of the scaled-drill bit.
Cutter/rock interaction models are validated with the acquired data from the cutter force sensing, enabling the evaluation of drilling efficiency while drilling different layers of rocks. Each cutter contributes to the weight-on-bit and torque-on-bit; thus, force sensing on a single cutter allows comprehensive performance evaluation for known drill bit design. The study of new and worn cutters provides insightful information on the drilling process in the cutter scale. In perspective, cutter force sensing might enable monitoring the wear evolution of individual cutters, which is impossible to detect with existing at-the-bit sensors.
The present work assesses the potential of integrating a force sensor at the cutter. The development of this work built the foundation for up-scaling research on cutter force monitoring.
Formation Evaluation from Logging While Drilling Prospective the Effects of Drilling Dynamics and Environment, Case Study from Abu Dhabi
Authors: Soliman Ahmed Mohamed , Khairy Hamad Awad , Elabsy Islam , Deng Lichuan , Ali Taif Yousif , Nazlan Firdaus 
Published: October 2022

Abstract
Wireline (WL) measurement emerged a long time before the logging while drilling (LWD) technology which created generations of petrophysicists with different school of thoughts. With the dramatic increase in the adoption rate of the advanced LWD technologies, highlighting the logging environment effects and revisiting our understanding of the formation responses logged under different borehole conditions are more critical than ever.
Hundreds of LWD datasets from various environments have been reviewed to identify its effects on data quality and responses from bottom-hole-assembly (BHA) design, driving mechanism, tool eccentricity, well angle, mud properties, differential invasion, borehole condition, formation fluid properties, and drilling fluids interactions. Some of these effects co-occur on many occasions, complicating the log response. Examples and demonstrations of our understanding and interpretation of these phenomena are discussed in the study.
Looking to the reservoir in the relatively fresh state, a few minutes after drilling with an understanding of the logging environment provides a unique opportunity to obtain precise formation evaluation and insight into reservoir behavior when combined with different time laps acquisitions.
This work is a continuation and addition to (Parmanand et al., 2018) which was extended to include more environmental factors in different oil fields and reservoirs with more advanced LWD technologies.
This work summarizes the long cumulative experience of interpreting LWD measurements, shares the main observations related to LWD responses and serves as a ready reference to identify measurement artifacts from actual formation responses. It is helpful as a reference guidebook for log analysts, geologists, geo-steering engineers, and others.
Slimhole One Piece Matrix Design Bit Technology Showed Significant Integrity and Performance Improvements in Coil Tubing Operations in Middle East
Authors: Rojas Pablo , Quintero Jonathan 
Published: October 2022

Abstract

Objectives/ Scope
This paper describes a new innovative concept, using a one-piece matrix slimhole design for a 3.625’’ PDC bit. This significantly increases durability and reliability, enhancing the bit life in multiple test analysis in highly abrasive lower Permian sandstone, driven by turbine and coiled tubing. The collaboration between the national oil company (NOC) and the drill bits provider results in achieving consistent records in footage and rate of penetration, without compromising bit integrity previously seem in sleeve designs.

Methods, Procedures, Process
A matrix sleeve design is the result of creating a single piece of bit using 100% matrix material adding TSP (Terminally stable Polycrystalline) in the gage pad protection, instead of using standards steel sleeve design with diamond grid discs protection. This concept allows the matrix sleeve to eliminate the cracks observed in the standard steel sleeve due the high temperatures generated while drilling into high abrasive sandstone environment with extreme parameters of rpm (1800 - 2000) as the turbine output. This provides enhancement to bit durability and integrity, due to the innovative use of higher resistant materials.

Results, Observations, Conclusions
After the first introduction, a qualifying trial test process starting in January and completed in September 2020, a microstructure evaluation was performed to evaluate the present of any field service cracks in the proposed one-piece matrix design, followed by full field deployment completing 12 wells in three different major fields. This resulted in setting the benchmarks of higher average footage of 354.61 ft (&gt;50% of improvement) and average penetrations rate of 14.44 ft/hr (&gt;25% of improvement) in abrasive drilling environment with zero integrity or reliability issues reported. After the deployment, each one-piece matrix bit has been physically inspected using the standard IADC dull grading format. More details of the performances, and bit inspections, will be presented in this paper.

Novel/Additive information
The innovative concept of using a one-piece matrix bit design delivers a much more reliable and efficient new technology, which significantly increased performance and successful deployments across this difficult drilling environment in these unique wells drilled in the Middle East.