bluuebunny/crossref_metadata_2025 huggingface dataset:
Overcoming Challenges in Managing Wellbore Stability Issues in Deviated 12-1/4" Hole Section while Drilling an Appraisal Well in a Sour Gas-Condensate Field: A Case Study
Authors: Richardson D. , Rosener A. , Louison W. , Al Ameri F.
Published: November 2015

In attempting to drill a deviated 12-1/4″ 37° tanget section with WBM through the Laffan and Nahr Umr shale intervals, very little margin for error was faced in a well where failure was not an option. While problems in the Nahr Umr were to be expected, the instability of the Fiqa and Laffan shale layers became the catalyst for excessive non-productive time. Two lost holes preceded the successful completion of the section after taking the last resort step of a re-drill with Synthetic Oil Based Mud (SOBM).

Various literature is available on wellbore stability problems in the Nahr Umr Formation on a regional and field specific scale. Behaviour of the shale and how best to control it is also known to vary on a field by field basis. Failure mechanisms are largely related to the mineralogical composition of the shale itself in combination with the localized geomechanical forces exerted on the specific wellbore. This paper captures the specific experience encountered in the operator's first well in the country and provides insight into the severity of the risk of wellbore instability.

Numerous operational issues were encountered due to shale instability induced through drilling and tripping related mechanical forces. Before committing to the changeover to SOBM, exhaustive attempts were made to find an acceptable and workable compromise to the challenges faced while drilling the section with WBM. This included implementation of alternative methods of well construction including the use of innovative tools and hole enlargement to increase annular clearances with the BHA. Often it was observed that mitigation of one problem led to the onset of another problem.

The experience is used to present an overview of the limitations of the contingency options available and the impact of unplanned changes implemented during the well construction phase.

In addition to the engineering conclusions presented, the case study provides insight into the complexities of a start-up drilling operation. Where an entire field appraisal campaign depends on the successful accomplishment of primary objectives, the necessity to perservere through adversity becomes of yet higher importance.
Investigation of Methods of Enhancing the Performance of Propane Pre-Cooling Refrigeration Cycles in Natural Gas Liquefaction Processes
Authors: Mazyan W. I. , Ahmadi A. , Ahmed H. , Hoorfar M.
Published: November 2015

This paper examines the viability of using low cost techniques to increase the performance (COP) of the overall natural gas liquefaction processes. Mixing propane with ammonia, sulfur dioxide or carbon dioxide and their effect on the compressor's required work is studied. The simulation results show that propane-ammonia and propane-sulfur dioxide mixtures enhance the COP by a maximum value of 7% and 9%, respectively. The COP enhancement in these blends is due to the closeness of their boiling temperatures with the operating temperature. However, the addition of carbon dioxide to the propane refrigerant reduces the COPof the cycle. This reduction is due to the poor energy absorption capabilities of carbon dioxide at the cycle operating temperature. The goal of this study is to investigate the feasibility of enhancing the COP using mixed refrigerants consisting of a hydrocarbon (propane) and natural fluids (ammonia, sulfur dioxide and carbon dioxide).
Using KCl to Mitigate Chemical Instability and Advanced Logging to Measure the Results in Well Top Hole Sections
Authors: Shaver Michael Alexander , Al Katheeri Yousif , Kvalvaag Edvin , Kustanto Sigit , Edwards Henry Ewart , Boyd Douglas Alexander , Shabaan Mohamed , Dasgupta Suvodip , Girinathan Sajith , Raina Ishan , Aziz Faiza
Published: November 2015

ZADCO's new field development program calls for drilling extended reach wells from artificial islands with the borehole kicking off at shallow depths and holding high inclination angles through the overburden. Previously, the development plan relied entirely on short reach, horizontal development wells drilled from jackup rigs with shallow overburden borehole sail angles rarely exceeding 30°. For both types of wells, bentonite weighted sea water is the preferred drilling fluid for the 16″ or 17.5″ diameter holes. Drilling problems that were managed in low-inclination wells became exacerbated at higher angles causing significant rig non-productive time (NPT). To improve our understanding of the shallow overburden formations, a comprehensive logging program was conducted in a key well drilled with a potassium chloride (KCl) mud system. Wireline borehole image, dipole shear sonic, spectroscopy and neutron-density-resistivity triple-combo logs were used to characterize the formations.

A successful logging program relies on maintaining the borehole in good condition. In this case, the KCl mud in conjunction with good drilling practices kept the hole near the 16″ bit gauge for 90% of the interval. Drilling mud losses were also minimized. The logging tools were successfully run to T.D. and the data acquired. The mineralogy of the penetrated formations was accurately quantified using spectroscopy tools. A high-resolution resistivity image log revealed that the entire interval was weakly fractured with a few zones of high secondary porosity and conductivity. These zones correlated well with zones of similar characteristics in offset wells. The key to drilling a high angle well lies is the geomechanical / geochemical characterization of the overburden formations to determine the wellbore failure mechanism(s).

This paper highlights the benefits of a KCl mud in the top hole and the results of advanced logging covering the predominately shallow carbonate formations that exist above a large carbonate reservoir. It emphasizes the need for characterizing not only the reservoir but the overburden formations. This advances drilling engineers’ understanding of formation characteristics so that increased drilling sail angles could be achieved through the shallow overburden and thus successfully reach the reservoir targets.
Internal Inspection - Can this be Achieved "Externally" for Pressure Equipment!
Authors: Shams Ahmed , Al Abri Ahmed , Coelho Jose' , Giridhar Y. V.
Published: November 2015

Legal Internal inspection requires pressure equipment shutdown, HSE clearance for safe man entry. These costs can be much higher than the cost of inspection itself. Furthermore, also mechanical damages can be caused during preparation for inspection and more importantly man entry in the equipment for examination is a health hazard.

Non-intrusive Inspection (NII) is an examination of a pressure vessel without any personnel entry, which can be applied whilst the equipment is in service. NII is a stringent engineering process in which inspection tasks are designed with the aim of replacement or deferment of a conventional internal visual inspection (IVI), where comprehensive planning and evaluation are carried out to ensure the inspection meets a specified criteria under an equivalent or higher level of confidence than IVI. NII technology has an extensive advantage if inspection is performed from the outside of the vessel without opening i.e. non-intrusively.
Advancements of Shell Cansolv in Post-Combustion CO2 Capture Technology
Authors: Abdollahi Farhang , Shaw Devin
Published: November 2015

An affordable and reliable Carbon Capture&Storage (CCS) technology is the key step to reduce CO2 emission from new and existing coal-fired and Gas power plant, as well as large industrial sources. With the milestone start-up of the Boundary Dam Carbon Capture and EOR project (Saskatchewan Canada, 2014), Shell Cansolv's technology became the world's first technology deployed in post-combustion carbon capture at commercial scale in the coal-fired power industry. This coupled with on-going operations in post-combustion CO2 capture for utilization in the industrial and chemical market, as well as an on-going front end engineering design (FEED) for CO2 capture from a combined cycle gas turbine (CCGT) power station. The Shell Cansolv CO2 capture technology has accumulated a spectrum of experience and learnings covering Enhanced Oil Recovery (EOR), CCU and CCS.

To open, this presentation will provide a project summary of Shell Cansolv in an on-going EOR, CCU and CCS application. Moreover, it will focus on the Shell Cansolv CO2 capture technology, providing a detailed technical description of how the line-up is adapted per application and provide rationale and relative performance indicators in each. A summary of the balance required to deliver the best Net Present Value (NPV) solution will be provided, such as the important considerations of optimization trade-offs on a per project basis, including: Increasing NPVOperations simplicityAcceptable Scale-up instead of multiple trainsEvolution in CANSOLV new solvents, their specifications and applicationsIntegration complexity vs. stand-alone robustnessA design for maximized availability, flexibility and cost-effective

In conclusion, a description of some of the key learnings accumulated in each application will be discussed, as well as an indication of where we think the next breakthrough changes can and will be made.
Well Performance Improvement Using Complex Nano Fluids
Authors: Kutty Shanof Mohamed , Kuliyev Myrat , Hussein Mohamed Abdelsalam , Chitre Sunil , Mustafa Hammad , Penny Glenn , Wehbeh Jamal , Germack David , Shedd Daniel , Lelenwa Chilezie
Published: November 2015

ADMA OPCO has started operations for a full field development plan in a green field located in offshore Abu Dhabi. All reservoirs are carbonates (dolomites and limestones) and thus acid stimulation is required post well completion in order to increase the well production/injection rate. During the planning stage, an extensive acid recipe study was carried out to formulate stimulation treatments to meet the challenging complexities of the reservoirs, high downhole temperatures and long corrosion protection time. Several lab tests were carried out to formulate all the acid recipes.

While in quest of new technology, an additive called ‘Complex Nano Fluid’ was introduced in the acid recipes based on proven case histories from around the world. This was also confirmed with the lab tests using ADMA reservoir crude and core samples. It is expected that by including nano fluids in matrix stimulation fluids, the overall productivity enhancement will be approximately 40% greater than conventional treatment approches. Most of the tests were performed in Abu Dhabi, however special wormholing tests with CT scan were done in a lab in Houston to evaluate the effectiveness of nano fluids on core samples.

This paper details the acid recipe work flow process, the different lab tests that were carried out to formulate the acid recipes, mechanism of complex nano fluid and its advantages.
SmartSulf™ Process in Direct Oxydation Mode for Very Lean Acid Gas Application
Authors: Heim Thibaut , Mares Benoit , Simonneau Vincent
Published: November 2015

Due to higher demand in desulfurization and new environmental regulations, Companies need to find robust and efficient technologies while considering the best approach to minimize CAPEX and OPEX. With more stringent regulations in terms of sulfur emissions to the atmosphere, some Companies have no choice but investing in new sulfur removal units. Some industries need to treat diluted acid gas with H2S concentrations below 15% vol. containing various impurities with, in some instances, huge hydraulic capacities. Some technologies can offer suitable solutions in terms of performance but investment and operating costs can be very high.

The SmartSulf™ technology used in a Direct Oxidation scheme can offer a proven solution for industries dealing with low H2S concentration (gasification, biogas, carbon black, natural gas…). The technology can be used in new facilities or, thanks to its low footprint, used in existing facilities for retrofitting. The core of the process is the implementation of a cooling system inside the catalytic reactor. Details and principle of operation of such cooling system are presented. The process configuration can also propose a sulfur subdewpoint mode where sulfur is directly adsorbed on the catalyst leading to higher recoveries. Based on a smart switching system, the process offers a simple and fully automatic operation allowing continuous adsorption and regeneration cycles.

Several configurations are available for the SmartSulf™ in direct oxidation mode based mainly on the acid gas H2S concentration and on the required performance.

This paper focus on the SmartSulf™ process used in direct oxidation mode and gives feedbacks from the existing facilities where the technology is already in operation for many years.
Corrosion Management Challenges of Non-Piggable Pipelines, Sections & Dead Legs
Authors: Dutta Rajdeep , Al Suwaidi Ibrahim Mohamed
Published: November 2015

Most operating oil and gas companies possess pipeline assets and In-line Inspections (ILI) are the most effective ways to assess the integrity of a pipeline. However to carry out ILI the pipeline should be piggable. Asset integrity audits have identified that while main pipelines are piggable most inter connectors, branches and by-passes are not in the pig’s path. Some sections while no longer in use, are still connected with the live system. These sections may be used rarely and therefore not an operational priority. However these ‘weak links’ pose a major threat to overall system integrity.

Many of these non-piggable pipelines do not have a corrosion control strategy and the technical integrity of most is unknown. This has been identified as a high integrity risk to operating companies with respect to loss of production, high cost of failure/degradation and high failure safety risk. As part of the technical integrity drive and risk management strategy, a need was identified to develop the strategy to assure the integrity of non-piggable pipelines / sections.

A thorough technical analysis made with advantages and limitations of available integrity assessment methods for non-piggable pipelines, such as: Hydrostatic Pressure Testing, External MFL Survey, Long Range Ultrasonic Thickness (LRUT) and Corrosion Direct Assessment (CDA). Based on the analysis, the most effective and techno-economic solutions were recommended and adopted by Dolphin Energy for its on-shore pipeline network in the UAE namely LRUT.

Dolphin Energy operates approximately 750 Km of gas transmission and successfully completed an LRUT inspection project - Phase-1 in 2012 comprising 9 locations and Phase-2 in 2014 - comprising 52 locations throughout the UAE. Post project assessment was made where LRUT inspection and corrosion direct assessment results were analyzed together. Post assessment specifically addressed the effectiveness of methods used, corrosion root cause analysis, a corrective action plan, remaining life calculations and determination of re-assessment interval of each non-piggable pipeline.

This paper addresses the new strategy developed and successfully implemented by Dolphin Energy to address the challenges associated with these non-piggable pipelines, sections and dead legs. Through this paper other operating companies who face similar challenges will benefit from the experiences of Dolphin Energy.
Design Approach to Overcome Brownfield and Shutdown Constraints
Authors: Subramanian T S , Adel Khalid , Al Awadhi Ibrahim
Published: November 2015

Performing major refurbishment works in brownfield, within limited shutdown window, pose challenges to the methodology adopted for the design and execution, especially if the structure involved is critical to Plant operations and requires significant modifications to ensure integrity / durability and minimise plant disruptions. This paper presents some such challenges and the methods deployed to overcome the same in one of the projects executed by GASCO.

Abu Dhabi Gas Industries Limited (GASCO) operates gas processing plants in the emirate of Abu Dhabi. At one of the plants, a burn pit is provided for emergency relief. The Burn pit was constructed in 1999-2000 and experienced frequent damages to refractory lining, leading to Plant outages for repair, thereby resulting in production losses. A technical study was carried out to evaluate different options for refurbishment and recommend a robust solution, considering the existing physical constraints and the challenging shutdown window requirements. The design phase involved exploring different configurations for the arrangements, discussions with refractory vendors to select the appropriate materials, and consultations with recognized contractors for the execution methodology and the duration.

The selected option involved complete demolition of the existing refractory and concrete structure, and replacement with a new concrete structure, covered with refractory lining. The concrete structure was designed and executed in pre-cast modules. The burner block, comprising of sleeve and castable refractory (for housing the burner tip) was also precast at contractor’s yard and dry-out during pre-shutdown phase was carried out. The pre-casting of modules allowed for pre-installation of anchors required to hold the refractory lining in position.

This option facilitated significant pre-shutdown works and ensured execution readiness during shutdown. As a result, all works involving demolition of existing structure, clearing the area of debris, construction of new structure using precast modules, application of refractory, etc. were completed and the burn pit was handed over to Plant operations three days ahead of schedule. This also contributed to cost savings, by maintaining long term integrity of the structure and reducing plant outages for maintenance.
A Novel Holistic Approach to Make Informed Business Decisions - Utilizing Formation Pressure Data from a Complex Giant Carbonate Field in Abu Dhabi
Authors: Ahmad Fazeel , Khan Muhammad Navaid , Sarsekov Arlen , Saif Omar Yousef , Al-Neaimi Ahmed Khalifa , Al-Alyak Abbas
Published: November 2015

The formation pressure testing data is widely used in the oil & gas industry to understand the reservoir vertical heterogeneity and the fluid movement within the reservoir. With the recent advances in formation testing technology, now the subsurface engineers are able to visualize the rock and fluid characteristics beyond the conventional few centimeters into the formation without putting the well on production.

A study for integrating all available formation pressure data was carried out in a field scale level. The holistic analysis of the data enabled the reservoir engineers to deduce critical information, such as, reservoir compartmentalization, reservoir depletion trend and the injectors’ efficiency.

The aim of this paper is to demonstrate a novel approach of analyzing formation testing data on a field scale from a complex reservoir that enabled ADMA-OPCO subsurface team to make informed decisions for better reservoir management. Certainly, the replication of this analysis approach could benefit the petroleum community in the similar field development scenarios.
Geological Mapping of Early Diagenetic Bodies as a Tool to Distribute Permeability in a Mature Giant Carbonate Field
Authors: Koppen J. van , Al-Menhali H. , Alblooshi A. , Caline B. , Guy L. , Kheidri H. , Hu T. , Kwasniewski A. , Dubois L. , San Miguel G. , Duval C. , Deviese E. , Thomas E. , Vanhalst M. , Dreno C. , Mel R. , Elhami M.
Published: November 2015

Revealing the coherency between geology and petrophysics in a mature carbonate field in order to provide 3D distribution of permeability is challenging.

This paper shows how integration of early diagenetic processes is a prerequisite in understanding the behaviour of a heterogeneous carbonate field. However, mapping of early diagenetic overprint requires the preliminary mapping of the main depositional belts per stratigraphic sequence as the relevant diagenetic processes occurred during or shortly after deposition. For instance, diagenetic processes associated with vadose dissolution or reflux dolomitisation significantly enhance matrix permeability of the reservoir. Mapping of diagenesis has therefore been used as a tool to constrain permeability distribution within depositional sequences in combination with the interpretation of available dynamic reservoir data. The resulting geomodel better honours the heterogeneities and the dynamic behaviour of the field.
Mud Weight Optimization to Reduce Non-Productive-Time While Drilling Through Shale/Carbonate Sequence of UAE: A Case Study
Authors: Xi GuiFen , labbassen Nabila , Al Badi Bader Saif , Lecoq Thierry Francis , Afifi Hassan Al-Husseiny , Al-Marzooqi Abdul Mohsen , Mais Nassim El , Mavromatidis Angelos , Ofield William , Rodriguez Jose
Published: November 2015

Maintaining wellbore stable is one of the key tasks in the oil and gas industry, in order to reduce nonproductive time during drilling, because wellbore instability problems would lead to higher than necessary drilling costs and have a severe impact on drilling schedule. Wellbore stability is controlled by two type of factors, one type is the factors which are completely out of our control, such as in-situ stresses, pore pressure, and rock strength, the other type is the factors which we can optimize and design to minimize geomechanical related stability problems, such as well trajectory, casing seats, mud system, mud weight, and proper drilling practice including minimizing swab and surge while running pipe and reducing the stationary time during connection.

In this paper, only the mud weight optimization and casing seats design will be focused on, in order to avoid geomechanical related instability issues for drilling a recently planned appraisal well in an offshore field.

Mechanical properties including Young's modulus, Poisson's ratio, USC, friction angle, tensile strength, bulk density and pore pressure gradient obtained from two offset wells A1 and A2 were projected to the planned appraisal well A3 with tops were used as guidance. The same parameters optimized from those two offset wells were used to estimate horizontal stresses for the planned well, and the same failure criterion was used to carry out wellbore stability for the planned well. Meanwhile the mud weight corresponding to kick, breakout, loses and breakdown were obtained. Based on those results, the safe mud weight window was established and the casing seats were placed to prevent and reduce the geomechanics related instability problems.

This methodology allows us to predict and prevent the geomechanics related instability issues in advance before drilling starts, thereby to reduce the non-productive time and drilling costs. Continuous updating of the geomechanical model is necessary during drilling if the geological environment is complicated.
Overcoming Technical Assurance Challenges in Executing Parallel Mega Projects
Authors: Awda Hisham , Almadhoun Wael , Al-Shehhi Khaled Mohamed , Shahin Malik Mohamed , Kotey Anthony
Published: November 2015

The successful delivery of mega projects is a challenging terrain. ADMA-OPCO continues to face numerous challenges of providing technical assurance to multiple mega projects running in parallel while meeting not only short and medium term expansion goals, but also ensuring a sustainable long term future.

The objective of this paper is to share ADMA-OPCO’s experience and success factors in driving Technical Assurance during projects execution.

At ADMA OPCO, the Discipline Engineering Division (DED) acts as the center of technical expertise in support of all ADMA’s business activities and in particular, in the delivery of the ongoing complex project programs. The DED is part of the Projects and Engineering Business Unit, in a seamless integration with the multiple project teams. DED is a custodian of Technical Assurance,Providing engineering & subject matter experts (SME) expertise to projects,Participating in project reviews and witnessing selected functional and performance testsDeveloping and updating relevant engineering technical codes & standards and assuring their compliance in all ADMA-OPCO projectsBeing actively involved in the technical evaluation and selection external contractors,Reviewing and evaluating project changes through a Management of Change (MOC),Ensuring consistency across projects in terms of technical compliance,Being actively involved in all project phases from idea development to execution,Managing inter projects interface issues utilizing access to overall long term plansActing as an authority for novel technology selection and adoptionAssuring the continuous improvement of the technical skill set within the company.

At ADMA OPCO, the current organizational setup of an integrated technical assurance provider and project teams is a model that is proving to be successful when executing multiple parallel mega projects.
Challenges & Complexity of World's Largest Flares Reduction Project
Authors: Howell Christopher , Vincent Andy , Goel Deepak , Hilleshiem Andrew
Published: November 2015

700 million standard cubic feet of valuable natural gas are flared each day in South Iraq as a byproduct of the region's oil production. At the same time, residents of southern Iraq suffer from a significant lack of power and at times can have as little as only a couple of hours of electricity per day. Iraq is now the 4th largest gas flaring country in a world of increased environment consciousness and the greenhouse gas emissions from these flares are equivalent to Croatia's total emissions.

Basrah Gas Company (BGC), a joint venture between South Gas Company (51%), Shell (44%) and Mitsubishi (5%), is a midstream gas company that aims to capture associated gas from three supergiant oil fields in southern Iraq – Rumaila, West Qurna 1 and Zubair. BGC is processing gas into valuable products of condensate, LPG, and dry gas to be used for power generation to the domestic grid. Approximately 5,000 Iraqi employees are seconded into BGC; these are much needed jobs and a valuable opportunity to transfer skills and capabilities into the region.

In 2015, just two years after commencement of BGC operations, much learning has been gained and progress has been made on all themes on the journey to increase safety, production capacity and operational excellence. This includes: Installation of new compressor configurations and rental machines to quickly add compression capacity.Priority scoping to rehabilitate the gas plants.Urgent work to recover process safety systems and safe work practices.Forecasting and planning projects to stay connected to the upstream gas supply from new oil developments.Maturing alternate growth projects - including a new green field gas plant.Developing operations systems that will assure production and maintain integrity.

From these examples it is clear that executing the world's largest flares reduction project requires novel thinking and excellence in project management. Furthermore, overcoming the increased challenges specific to the region, impacted by decades of war and economic sanctions, has brought enriched learning for the company and beyond. These capabilities in project execution built on this early experience are a sound foundation for project delivery.
Innovation to Bring a Pivotal Gas Capturing Project to Iraq
Authors: Kock Arne de
Published: November 2015

The residents of Basrah, Iraq, suffer from a significant lack of power and at times can have as little as only a couple of hours of electricity per day. Utilising one of Iraq’s most abundant natural resources is a key value driver as Shell works closely with the Iraqi Government, the National Oil and Gas Company (SOC & SGC), and several other significant stakeholders, to deliver more gas to the domestic grid, faster than previously thought possible.

The Tigris First Commercial Production (FCP) Gas project scope involves gathering sweet associated gas produced from the Majnoon field, before sending it to a newly built 1.2 GW power station at North Rumaila. In addition to major improvements to the current energy infrastructure, impacted by decades of wars and sanctions, the project will reduce emissions associated with flaring by putting the gas to use.

Traditional methods for building a gas plant would not deliver on the needs of our major stakeholders - to have access to gas on the shortest possible timeline for local power. The project demanded a radical approach. An answer was found in a novel, fully modularised marine barge concept which had potential to deliver on the tight timeline required.

The final concept for Tigris (FCP Gas) involved building a fully modularised 140 MMSCFD gas plant with our partners, Solar in Houston. The plant was equipped with compression and dehydration capability. The system was built, tested and dismantled into smaller structures. In addition to a fully modularised gas plant, a fully-modular, six-finger slug catcher was manufactured in Kansas for installation at the power station in North Rumaila. All these modular pieces, assembled in two separate locations across the United States, had to be made for easy re-assembly and to fit within the space and payload restrictions of the Antonov aircraft. The Antonov made 40+ round trips between the U.S. and Iraq to transport all the equipment for final installation and commissioning.

Innovating to a novel, modularised concept that would be fabricated in America and airlifted to Iraq by multiple Antonov roundtrips, proved to be extremely successful and has allowed the team to work towards an achievable timeline, about half the original duration, to domestic gas delivery.
An Economic Approach to Horizontal Well Length Optimization
Authors: Dosunmu Idowu , Osisanya Samuel
Published: November 2015

Horizontal wells offer higher productivity when compared to vertical wells due to increased contact area with the reservoir. It is now accepted that an increase in well length is not proportional to higher productivity after a certain critical well length because of frictional pressure losses in the wellbore. As the well length increases, so does the frictional pressure loss. In most cases there is an optimal well length beyond which a productivity decline will occur. The purpose of this study is to present findings on horizontal well optimization taking into consideration frictional pressure loss effects with and without perforations in the wellbore. Several horizontal well productivity equations can be found in the literature. In this study a productivity equation based on an elliptical drainage area is assumed. Other assumptions include single-phase incompressible oil, isothermal condition, and homogeneous reservoir with directional change in permeability. Parametric studies were conducted to investigate the effects of pressure drawdown, wellbore diameter, horizontal permeability, formation anisotropy, and oil viscosity on well performance. A probabilistic economic approach based on net present value (NPV) is used to determine the optimal well length for a particular set of reservoir and well parameters that will be useful for planning and designing horizontal wells.

Results show the following: Horizontal well productivity is significantly affected by oil viscosity, horizontal permeability, and well diameter. Those parameters must be considered for the optimization of horizontal well length.Frictional pressure losses have a significant effect on the productivity of small diameter wellbores in high permeability formations containing relatively low viscous oil.Sensitivity analysis of economic parameters indicates that oil price had the greatest effect on NPV at a particular well length. Production taxes and operating costs ranked second and third, respectively, with negative effects on NPV.
Development of Tightly-Coupled Integrated Asset Model For Use in Production Optimization, De-Bottlenecking and Flow Assurance of Multiple Gas Reservoirs
Authors: Zadeh Seyamak Gholam , Barzanji Diyar , Brock Nigel , Ateeq Budour Omar , Bloch Gerard , Abu-Snaineh Adel
Published: November 2015

This paper presents the development of a tightly-coupled Integrated Asset Model (IAM) to capture the surface-subsurface interactions of 5 gas condensate reservoirs producing through a common surface facilities network. The objective of the exercise is to develop a tool that is built to combine existing compositional simulation models and the surface network model in a single platform/environment that could be used in production optimization, de-bottlenecking, field development and flow assurance.

The success criteria included providing a solution that can ensure: Adequate representation of the different fluids of the 5 reservoisFull adherence to existing network constraints and field development guidelinesProviding optimal network configuration based on the use of automatic production optimization procedures.Flexibility to add complex network elements and decision logic

The most powerful and unique feature that enabled all of the above was the effective use of procedures and built-in functions in Nexus that offer the capability to incorporate operational considerations into the solution.

The first step involved developing a common fluid components basis to be used for the surface and subsurface models. This was achieved through adopting a suitable lumping scheme that involved minimal adjustment to the existing equations of state (EOS) and no compromise of the fluid description or the quality of the history matches

Next step involved converting all the five reservoir models and their surface network model into the same simulation environment. The final step involved developing the procedures that carried out production optimization and proposed the optimal settings to fully utilize the available compression capacity.

Finally, the surface elements of the IAM were calibrated to the results of production capacity tests. The calibration involved matching the observed gas production rates, tubing head pressures and flowline pressures. This step is required to validate the constrained model performance and prediction.

The results showed the magnitude of interaction between the reservoirs and clearly identified the system bottlenecks. The model can be used to propose the best tie-in location of future wells in addition to providing first-pass flow assurance indications by highlighting elements of the network at risk of erosion throughout the field's life and under different network configurations.
Connected Destinies: Reducing Road Trauma in Basrah by Highlighting Family Bonds
Authors: Macklin Stephen
Published: November 2015

This paper describes the production of a seatbelt safety media campaign which is a joint initiative of Shell, Iraq and the Basrah Traffic Police Directorate. The media campaign enhances existing road safety initiatives in the Basrah Province of Iraq implemented in partnerships with government, non-government and multi-lateral agencies.
Inorganic Scale Challenges and their Mitigation in an Onshore Abu Dhabi Field
Authors: Abdallah Dalia , Elechi Collins , Graham Gordon , Simpson Caroline , Kidd Sam , Hoeth Laurien Wichers
Published: November 2015

Inorganic scale precipitation has been observed in an increasing number of wells in an onshore Abu Dhabi field. Mitigation strategies have historically concentrated on laboratory analysis of scale samples and design of remedial acid treatments in combination with mechanical methods to clean out the wellbore. To evaluate success, well accessibility and production improvement checks are made before and after the job. This reactive strategy has had mixed results, and the emphasis is now shifting towards use of preventative techniques especially with the increase in Water Alternate Gas (WAG) and Artificial Lift (AL) operations, increased water injection and produced water re-injection.

Detailed evaluation of the scale risk has been conducted via scale prediction modelling identifying that the major risk relates to calcium carbonate scale due to pressure reduction during production. In order to mitigate this risk, and to be able to minimise productivity losses and increasing costs associated with remediation treatments, the decision was made to evaluate the potential for scale prevention via downhole scale inhibitor application by squeeze treatments for naturally producing wells and by continuous injection for artificially lifted wells with Electrical Submersible Pump (ESP). Extensive 3rd party laboratory qualification of 8 different vendor recommended scale inhibitors for each application were carried out and the results will be presented in this paper. There were challenges faced during the testing of the scale inhibitors for squeeze application because the vendor supplied formulations had poor injectivity and led to formation damage during initial core flood tests. The 3rd party lab re formulated the vendor chemicals to minimise the potential for formation damage. Further core flood testing with the re formulated chemicals resulted in minimal formation damage while maintaining relatively long scale inhibitor squeeze return lifetimes. This work illustrates the importance of extensive chemical testing prior to field application to avoid any problems in the wells.

The laboratory qualified scale inhibitor chemicals are planned to be trialed in wells which have been identified with a carbonate scale risk based on historical data or on results from prediction models under particular production conditions. The ultimate goal is to have in place a robust inorganic scale mitigation strategy as part of the field development plan to minimise well intervention and increase well availability.
ADCO First Hydraulic Fracturing Campaign Strategy in Unconventional and Tight Migrated Oil Reservoirs from Planning, Designing to Execusion, Challenges and Mitigation
Authors: Hegazy Gehad M. , Noufal Abdel Wahab , Shedid Shedid A.
Published: November 2015

Unconventional reservoirs in North America showed excellent results through the late decade. Tight carbonate and source rocks in the UAE with very low clay content involve more comparative challenges. Evaluation and application of Fracturing technology on these reservoirs require accurate designing, planning and execution. These three phases are followed by a unique strategy for cost optimization especially when oil price drops.

To enable a detailed understanding of these formations and the applicable fracturing methodology, a complete study and strategic map is required. Unconventional reservoirs in North America have been studied extensively. The challenge is to adapt this technology locally to our tight reservoirs at ADCO-UAE. Creating a fracturing workflow and strategy that is applicable to the tight and unconventional formations in the UAE is the main target.

Fracturing technology evaluation of these reservoirs has their own set of challenges, ranging from creating valid geomechanical properties to building the Mechanical Earth Modeling (MEM) for successful execution. Screening of suitable candidates as sweet spots and unique data gathering under cost effective programs is presented in details. The first five wells' plan, design and execution are highlighted. Furthermore, the integration of fracturing steps and the lessons learned are elaborated in this paper.

The paper highlights complete evaluation of the fracturing process of tight carbonate reservoirs that reveals the unique challenge of developing these reservoirs from a Reservoir Quality point of view. Furthermore, the paper presents complete study, strategic map, screening, fracturing workflow, and strategy for several wells fractured.
Precipitating Carbonate Process for Post-Combustion CO2 Capture. Techno-Economic Evaluation
Authors: Davila Ytalo , Grigoriadou Katerina , Olfos Tomas , Schoon Lodi , Infantino Melina , Last Tim , Mitkidis Georgios , Martavaltzi Christina
Published: November 2015

Commercially available post-combustion CO2 capture technologies are based on aqueous amine solutions. One of the main cost drivers of such processes is the energy required for solvent regeneration. Most advanced technologies currently claim regeneration energies between 2.7 and 3.2 MJ/kg of CO2 for separation of CO2 from a Natural Gas Combined Cycle (NGCC) power plant flue gas. A system comprising a precipitating carbonate-based solvent has been claimed to have energy consumption well below 2.5MJ/kg of CO2. Here, the concept is evaluated to quantify its potential to bring down the cost of CO2 capture. A process model is developed based on correlation of available thermodynamic data to perform heat and material balances and to define the process operating window. Furthermore, experiments were carried out in a bench scale unit of 25kg/d (2.77x10−4 kg/s) CO2 capture capacity to demonstrate the integrated process concept. Finally, a techno-economic evaluation is performed based on the design of a commercial scale unit of one million tons per year (33.07 kg/s) CO2 capture capacity. The results indicate that the technology has not only higher energy requirements than originally claimed, but also higher capital cost than state of the art amine based systems. Thus, it is decided to stop further development of the technology.
Bending Rules with High Build Rate RSS
Authors: Tipu Imran , Alawadhi Eman , Kumar R. , Amanov Batyr , El Gebaly Mohamed A. , Al-Hammadi A. M. , Shamlan A. M. , Danche Ali M. , Ganda Sukesh , Dua Rajan , Hariri Nour
Published: November 2015

The introduction of a high build rate rotary steerable system (HRSS) capable of delivering in excess of 18°/100 ft DLS resulted in the expectation that this will lead to drilling more wells with higher DLS with RSS. While this paper is not to explore this expectation, it is obvious that this rotary steerable system (RSS) has been used by E&P Operators in the Middle East Region for so many different applications within the operating window of the other existing RSS system. This paper aims to explore in details the unique and ingenious applications, benefits and value of these HRSS systems to the clients in the UAE in terms of optimizing costs and improving drilling efficiency.

The traditional method of utilizing a motor for kick-off, sidetrack and exit whipstock was challenged and the broadened operating limits of HRSS were utilized to its full potential to find ingenious ways to perform such operation. The major benefits from these applications are a result of the ability to overcome challenging drilling environments or operational requirements. 22 jobs have been completed in the UAE from Q1, 2012 to date using the HRSS with 100% success rate across the range of applications described below:- Dogleg severity assurance in complex 3D trajectories or through incompetent formations.Kick-off from vertical in various formations with different comprehensive strengths.Cement plugs sidetrack from vertical and shoe to shoe drill ahead to section TD.Sidetrack from whipstock with15 ft rat hole and shoe to shoe drilling with full suite of logging tools.

The increasing demand for this service and creation of a niche, even in the current environment of demanding cost optimization and value based technology, the application of this technology has led to an estimated saving in excess of 40 days. The non-tangible benefits include better hole cleaning and smoother wellbores leading to less wellbore tortuosity and improved ability trip post drilling with drilling, logging and casing assemblies. The asset teams are not left out as the near bit measurements in theses assemblies also aid in reduction of the uncertainties and enable better decision making, especially while landing the well or at TD point selection.

The applications of HRSS described in the paper are innovative applications designed through immaculate planning and risk mitigation. As a result of which significant achievements in cost optimization and drilling efficiency enhancement have been realized.
The Road to Digital Asset Reality
Authors: Elnaggar Basem , Farshoukh Ahmad , Almadhoun Wael , Al-Amry Mohamed
Published: November 2015

As-built engineering information is mission critical to safe, reliable operations. Due to inevitable modifications throughout an asset's life, the quality and availability of as-built information erodes over time and is no longer indicative of the actual as-operated facility. This paper highlights the new technology, methods and processes in as-built campaigns. Also, it explains why it is necessary to move from a document-centric to data­ centric approach in engineering information management.

Abu Dhabi Marine Operating Company (ADMA-OPCO) as-built approach is illustrated utilizing laser scanning technology, consolidating the legacy engineering information combined with site survey data capture to build intelligent databases, 3D models and 2D engineering deliverables. ADMA-OPCO leverages these data silos into an ElMS (Engineering information Management System) to provide a single source of organized and interlinked as-built asset Information. ADMA-OPCO implemented procedures for quality assurance through data completeness, consistency across various sources, reporting and solving the issues impacting information integrity and reliability.

Having a digital asset throughout the life cycle of an operating plant creates a sound basis for asset modifications, reduces the need of site visits for data collection and site surveys, minimizes the exposure of engineering personnel to potentially hazardous environments and provides quick and high quality input for decision making. The paper reveals the limitations of a document centric approach to management of asset information and explains how rigid, non-integrated information databases lead to data silos and the impact on the as-built information quality, resource productivity and operational safety.

This paper raises awareness of the benefits of utilizing the digital asset to gain instant access to asset engineering objects and their associated references. The digital asset can be used to support effective decision making and ensure data is centralized, accurate, change-controlled and highly accessible in the context of the processes it supports.