bluuebunny/crossref_metadata_2025_split huggingface dataset:
Turbodrill Bottomhole Assembly and Real-Time Data Improve Through-Tubing Coiled-Tubing Drilling Operations in Sour Gas Well
Authors: Ebrahimi A. , Schermer P. J. , Jelinek W. , Pommier D. , Pfeil S. , Flint G. 
Published: November 2015

Abstract
Through-tubing (TT) drilling was used to drill Upper Permian Zechstein carbonates in Germany. The project was partially set up as an experimental performance comparison between a positive displacement motor (PDM) and a turbodrill bottomhole assembly (BHA) equipped with real-time logging tools. This would be a world-first drilling run for this size of turbodrill as well as the first turbodrill run on coiled tubing (CT) using this real-time data feedback.
Through-tubing coiled tubing (TT-CT) drilling incurs significantly lower cost per drilled footage than conventional rotary drilling methods. A dedicated candidate selection process emphasized the geometry and extent of the pay zone, borehole stability, tubing geometry, and well integrity, which are all crucial for the application of TT-CT drilling. As a result of this screening process, well Sh Z1a, a horizontal sour gas production well was selected. Dedicated BHA designs were used for both the PDM and the turbodrill to allow for a direct performance comparison whilst drilling the section.
TT-CT drilling was used to deepen the well. Initially, 410 ft [125 m] were drilled with a 2.283-in. [58.0-mm] impregnated bit and a 2.125-in. [54.0-mm] PDM using 1.750-in. [44.5-mm] CT suitable for sour service. An additional 148 ft [45 m] were drilled with a 2.283-in. [58.0-mm] impregnated diamond bit with polycrystalline diamond compact (PDC) cone cutters. This bit was run with a 2.125-in. [54.0-mm] turbodrill BHA equipped with real-time logging tools using a sour-service-suitable 1.750-in. [44.5-mm] CT with a fiber-optic cable. The section was drilled under total losses and through multiple natural fractures. While drilling with the real-time logging tool, internal and external downhole pressures, torque, and tension and compression forces were recorded to assist in the drilling process. Direct comparison of the PDM and the turbodrill BHA was made for rate of penetration (ROP), weights and pressures. The turbodrill BHA produced more than double the ROP than was possible with the conventional PDM BHA using less weight on bit and showed overall smoother drilling mechanics.
The well is currently on production. The project showed that TT-CT drilling is a viable technology for production enhancement in depleted gas reservoirs and that new turbodrill technology generates significant performance improvements over conventional drilling tools.
Integrated Approach to Evaluate Unconventional and Tight Reservoirs in Abu Dhabi
Authors: Steiner Stefan , Ahsan Syed Asif , Noufal Abdelwahab , Franco Bernardo , Koksalan Tamer , Amjad Kashif , Helja Emina , Alhosani Sabah , Adesanya Akindele 
Published: November 2015

Abstract
ADCO has drilled a number of wells and evaluated hydrocarbon potential of the Middle Cretaceous Wasia Group Unconventional reservoirs onshore Abu Dhabi since 2012. Latest logging and core analysis technologies were applied to assess key parameters such as Total Organic Carbon (TOC), source rock maturity, mineral compositions and fluid saturations, as well as geomechanical parameters such as Young's modulus, Poisson's ratio and minimum horizontal stresses. To date more than 2500ft of core has been extracted, described and analysed. We understand that ADCO has, by far, the largest data base among all the OPCOS with regards to unconventional play and has gained a significant local learning curve ahieved over the last 3 years.
In addition to triple combo data, log data acquired consists of NMR, high resolution lateralog, dielectric logs, and mineral spectroscopy, cross dipole sonic, borehole imaging and sonic scanner, routine and advanced mudlogging. Core analysis consists of crushed rock analysis, pyrolysis and rock mechanics testing. Significantly high mud gas readings, observation of oil staining, odor, and fluorescence under UV light indicate presence of oil over large sections of the acquired cores and side wall cores from various geographically spread wells. Recently, we have conducted 5000 TOC and 1500 Pyrolysis measurements from core and cuttings samples in 110 wells spread all over Abu Dhabi. This data clearly demonstrate that large sections of Wasia Group bear excellent source rock quality in several wells located in large segments of onshore Abu Dhabi. Visual inspection of core and TOC measurements indicate that high frequency jet black centimeter scale organically rich lamellae often exceeding 20% TOC in several wells are not uncommon. The unconventional reservoir rocks are composed of predominantly clean and tight matrix carbonate mudstones and wackestones. Preliminary results of the current exploration campaign within the ADCO concession are very encouraging, showing indications of hydrocarbon presence. Formation testing is planned in the near future to confirm the Unconventional play in Abu Dhabi.
The paper focuses on an integrated multi-disciplinary approach covering petrophysical, geological, geochemical and geomechanical assessment with the ultimate goal to determine optimal parameters for formation testing and production.
Well Integrity Support by Extended Cement Evaluation - Numerical Modeling of Primary Cement Jobs
Authors: Godoy R. , Fontan M. , Capra B. , Kvalsund R. , Poupard O. 
Published: November 2015

Abstract
The cement height requirements for primary cement jobs, or annulus cement, are stated as absolute values in some parts of the world. For example the Norsok Standard, D-010, "Well integrity in drilling and well operations" states that one cement barrier is either 50 meters when verified by displacement calculations, or 30 meters when verified by bonding logs. The requirements do not distinguish between reservoirs with high pressure/ temperature- and reservoirs with typical low pressure/termperature conditions. A numerical method has been developed which considers the current or future well conditions as part of the cement evaluation process. This numerical approach is an additional tool in the decision making process and does not replace existing verification practices. The time to run the analysis has also been an issue to address, since existing tools in the industry (FEM-analysis etc.) can be quite time consuming to run. Additionaly it is also possible to perform analysis up-front the operations and various pre-defined cement length intervals can be compared to the requirements or other upper acceptable cases. Offshore well cases from the Norwegian Continental Shelf have been used as basis in the development and demonstration of the method. The numerical model is based on monophase or multiphase Darcy flow calculations through the cement sheath involving uncertainties like cement permeability, reservoir pressure in the eternal perspective etc. The model allows a parametric analysis in a reasonable computation time and building of a well case library making the process efficient in an industrial comparison perspective. The method is an ‘engineering approach' taking place in the decision making process of well integrity.
Ultimate Use of Pressure Testing While Drilling for Green Field Reservoir Development
Authors: Kilic Akgun , Amer Mohamed Mostafa , Al-Jaberi Salem , Ahmed Husnein Shershad , Clemens Carter , Zidan Maher , Shuaib Mohamed , Vicario Roberto 
Published: November 2015

Abstract
Pressure testing while drilling provides pressure depletion data to better understand the communication between wells and sublayers. In a green field, it may even substantially optimize the well completion and reservoir management strategy.
Pressure testing while drilling (PWD) was performed in a highly deviated well crossing eleven sub-layers of the same reservoir in a new field. An NMR tool was also used for porosity and qualitative permeability measurement and shows a clear seal between the subjected zones. Pressure measurement was conducted at least in two locations of each subzone and draw down mobility for every test was calculated. Pressure data from tested well were compared to initial pressure data from pilot holes and indicated strong depletion from three sub-connected units. The test tool had the flexibility to re-orient if good seal was not achieved during the test.
The successful results from a 3000 ft 6″near horizontal drain demonstrated the ultimate use of pressure testing while drilling could clarify differential depletion among different sublayers. At a different scale, this will enhance reservoir management, optimize well completion and save rig time.
Pressure testing while drilling is an important part of the reservoir monitoring plan in order to get accurate static pressure at the reservoir which can be used to monitor reservoir pressure to understand the dynamic communication and depletion per layer. The objective is to make pressure measurement while drilling a standard procedure for all future wells of the field. The conclusive findings from this study considered to be a good integration practice that will help to improve completion strategy, reservoir management and eventually the reservoir modeling.
Materials Selection for High Pressure Sour Service in the Shah Gas Development Project
Authors: Sahoo Tareq , Keat David , Al Romaithi Saeed D. , Pandey Shyam 
Published: November 2015

Abstract
Al Hosn Gas Company, a 60/40 JV between ADNOC and Oxy has been undertaking a project for the development of an extremely sour gas reservoir in order to increase production of injection and sales gas. The Al Hosn Gas plant is designed to process 1,000 MMscfd of non-associated sour gas.
The gas reservoir is very sour with H2S levels of 23% together with 10% CO2 and other corroding components such as 20,000 ppm chlorides and 5 bbl/MMSCF water.
The bottom hole conditions make the overall environment very aggressive for any conventional material e.g. carbon and alloy steels.
Processing of such sour feed posed a significant design challenge. Materials selection for production tubular, gas gathering lines and process equipment was the main strategy to ensure plant integrity.
The well fluid can reach high temperatures. To protect against external corrosion the carbon steel backing material for flow and trunk lines was coated with high temperature epoxy.
Four exotic materials were selected and subjected to 30 days exposure test in autoclave at simulating gas gathering lines conditions. Two materials were further subjected to closer scrutiny with a series of potentiodynamic polarization tests and metallurgical analysis.
This paper deals with the materials identification evaluation, test procedures, test details and final selection together with applicable fabrication procedures.
Real-Time Integrated Optimized Drilling Technology for Deep Carbonate Formation
Authors: Wei Liu 
Published: November 2015

Abstract
For deep carbonate formation, there are many drilling problems in applications, such as hydrogen sulfide distribution, narrow pressure window, strata complex, objective layer pressure sensitive, which lead to drill ahead and improve the rate of penetration (ROP) very difficultly. And carbonate reservoir comprises many fractures and caves which must be connected as more as possible to form a longer petroleum channel for increasing single well production.
In order to solve above problems, an integrated optimized drilling technology is raised to realize these challenges which includes three important points of innovation. Firstly, it is the horizontal well optimized design along top boundary of fracture-vuggy formation to realize the longest horizontal section because of petroleum inside fracture or vuggy. Secondly, it is to increase ROP by minimal mechanical specific energy and micro underbalanced pressure drilling method to optimize drilling parameters. Thirdly, it is to develop managed pressure drilling (MPD) in complex conditions to monitor annular pressure in real-time and keep downhole pressure constant or whole circulation flowrate stable.
The new design can help us get more opportunities to increase the production of single well effectively. The real-time integrated control method can realize ROP significantly, such as get about 39% improvement than before in Tarim oilfield. If no harmful gas or a little harmful gas come out from formation, micro underbalanced pressure control drilling technology may be most applicable method to develop deep carbonate formation because it can control well kick at a small rate to find pay zone, keep well wall stable and improve ROP. In sum, after many field applications in deep carbonate formation, it is proven that the integrated optimized drilling technology can break through the traditional drilling technology to extend horizontal section as long as possible (present record of longest horizontal length is 1561m), find more pay zones and overcome the drilling problems in deep carbonate formation to realize safety and fast drilling and gain maximal economic benefits.
In contrast to conventional real-time control method, the new technology considers the design about how to extend the horizontal section length along the top of frature-vuggy structures which is safety and effective in reality. At the same time, we adopt new real-time parameters optimization and managed pressure drilling to solve different problems and also improve drilling effect. Therefore, especially for deep carbonate formation development, the new real-time optimized integrated drilling technology should be gotten more and more applications for develop effectively.
Multi-scale Geomechanics: How Much Model Complexity is Enough?
Authors: Hoedeman Gerco 
Published: November 2015

Abstract
Nowadays oil and gas exploration and production is often performed in geomechanically challenging enviroments where the risks can be high and problems are costly. Choosing the right scale and complexity of a model is critical for performing an effective and efficient geomechanical analysis that addresses the problem without unnecessarily expending resources like time, computation power or software license costs.
In this paper different geomechanical modeling techniques are compared for their accuracy and efficiency using a relatively simple (continental slope) and a more complex geological setting (submarine canyon). This has been done by comparing the resulting state of stress of 1D well-centric geomechanical models with those of reservoir-scale 3D geocellular and 4D finite-element models.
The more complex submarine canyon model shows that in relatively complex areas the 1D and 3D geomechanical models no longer give accurate stress results and a 4D model is needed to accurately simulate the state of stress. On the other hand, the continental shelf model shows that in a simple geological setting creating a 1D wellbore-scale geomechanical model is an efficient and effective way of calculating stress. The 1D model gives an accurate state of stress comparable with the more complex 3D and 4D reservoir-scale geomechanical models. Not having to create, simulate and analyze a reservoir-scale model can save time for better analysis of the results, dealing with uncertainties of the model and/or doing a sensitivity analysis.
The paper concludes that the initial step in a geomechanical study is assessing the geomechanical application of the model, taking the complexity of the geological setting into account and based on that assessment chosing the modeling complexity that is necessary to get accurate results, without unnecessarily spending resources.
Unlocking the Potential of Marginal Reservoirs in Kuwait Through the Application of Optimized Hydraulic Fracturing Technologies
Authors: Al-Othman M. , Al-Houti N. , Anthony E. , Aloun S. , Mokhtar A. , Sheikh B. 
Published: November 2015

Abstract
In Kuwait, drilling and deployment plans focus mainly on drilling vertical wells through a wide range of reservoirs consisting of high- and low-permeability sandstones and carbonates, with varying crude types from medium-heavy to condensate. Since 1935, Kuwait has produced mainly from the types of reservoirs that keep its daily production as high as possible to accommodate the country’s economic needs. With the aging of these mature reservoirs, reservoir pressure reduction and water production become a major challenge, in addition to the limited access to drilling resources. Accordingly, exploring different reservoirs and unlocking the potential of the existing low- to mid-permeability reservoirs through advanced fracturing technologies are considered the alternative plan to compensate for production decreases and to improve oil production. However, implementing such technologies requires a customized design and candidate selection process.
The plan involved a multidisciplinary well candidate screening and selection criteria for different reservoirs and fields. The criteria include different parameters such as bubblepoint pressure, minimum formation thickness, and rock mineralogy, in addition to the study of the previously applied production enhancement technologies. About 50 wells have been selected from different reservoirs and fields across Kuwait for the initial pilot plan to evaluate the potential of a wide range of reservoirs. Then, a customized fracturing technology design followed that included operational planning, execution, and evaluation.
Approximately 20 fracturing treatments were executed successfully, and the post-job evaluation showed two- to four fold gains in production. This changed the development strategy and allowed for further development plans for these reservoirs. These newer plans included the application of technologies such as channel fracturing for proppant fracturing and fiber-laden self-diverting acid system for acid treatments.
The well candidate selection criteria and customized design of channel fracturing technology for the sandstone reservoirs and fiber-laden self-diverting acid system technology for fractured carbonate reservoirs resulted in a total additional gain of approximately 15,000 B/D. The detailed engineering design from candidate selection to treatment and the application of optimized hydraulic fracturing technologies enabled production enhancement and additional recoverable reserves from the most challenging low-permeability and low-API gravity candidates for the first time in Kuwait where conventional stimulation techniques were not providing the expected results.
Systematic Approach to Early Identification of Control Systems Interfaces for Large Brownfield Oil & Gas Projects
Authors: Mukunda V. , Panditaradhyula S. S. , Tighilt M. , Thallapalli B. , Das A. K. , Al-Akel M. A. 
Published: November 2015

Abstract
We have 2 major fields Zakum and Umm Shaif which are one of the biggest offshore reservoirs in the world. Our brown field challenges in offshore are limited to those fields. In addition to which there are numerous new green field projects which are also in the pipeline.
One of the main challenges in any brownfield project (big or small) is to avoid the unexpected changes or "surprises" that are often uncovered during detailed design or worse-still during offshore construction. These surprises tend to cause projects to recycle, exceed budget and/or extend schedule. More importantly, they can affect the ability to obtain an inherently safe design where the risk is ALARP.
This risk can further increase as the facility ages and modifications are made. As new projects come to the existing facility, the proposal for new equipment and hazards can make it extremely challenging to find the best solution for both the existing facility and the project.
There are myriad challenges faced in any brownfield project- Shortage of space, shortage or lack of electric power, pressure on production which will make brown field schedules unviable and lastly the hazardous nature of the industry which is a factor to be considered for all scenarios.
Energy Management System
Authors: Al Ameiry Ahmed , Al Breiki Hana , Abdulla Haitham Salmeen , Ali Nafisa 
Published: November 2015

Abstract
Energy is an essential business input. A strategic approach to energy use can improve profitability and reduce environmental impacts, despite the task being herculean, involving careful planning, unified approach between departments and above all, addressing the issue of resistance to change. ADGAS implemented an Energy Management System (EnMS) which not only covers plant operations but considers each and every aspect of the organization. Equipped with procedures, tools and manuals, the system went beyond to plant the concept of energy efficiency and conservation to the minds of employees working in different departments. The achieved savings of 12,670 TJ for the first 6 months in of 2015 helped in a reduction of 57,000 tons of CO2, GHG emissions. More than 90 Energy Performance Indicators had to be created along with corresponding baselines and then Significant Energy Users were selected to focus on improving the energy performance durng the course of a calendar year. On the whole, it was a tough task but the efforts of ADGAS team made it possible. The management also showed its commitment by issuing ADGAS Energy policy along with following up progress and outcomes on semiannual basis. After developing a robust energy management system, the way forward is to develop an energy transformation strategy and ensure continual improvement of the system through audits either internal or external.