bluuebunny/crossref_metadata_2025 huggingface dataset:
From ATI to ATA: Building the Next Generation of Operators and Technicians
Authors: Laurent Stephane
Published: November 2018

ADNOC's proactive response to worldwide changes affecting the industry is to enhance operational efficiencies, optimize costs and improve performance. The ATI (ADNOC Technical Institute) to ATA (ADNOC Technical Academy) transformation project is part of this response and aims to provide ADNOC with a sustainable workforce to run its business by applying an approach to training that is based on competency and performance, and where OJT (On the Job Training) plays a crucial role.

The major achievements of the transformation after the first year of its implementation are: –Implement a new curriculum that is shorter, more efficient and fully aligned with end-user needs and expectations.–Rationalize practices to optimize costs, implementing a high performance-driven culture that values good work habits and improve attitudes and commitment to HSE.–Strong efforts in rehabilitating the large majority of existing trainees (84%) to "jump the curve" and make it to the new program despite the enhanced requirements–Instil a culture whereupon students are trained to understand the importance of being accountable, working in a team, communicating effectively with others, taking initiative, knowing their strengths, building goals and ambitions and working hard to overcome their identified weaknesses.–Engaging 9 operating companies to accommodate 400 trainees on their 13 sites for OJT–Change in organizational culture by which staff and students are accountable and responsible to meet specific performance standards.–Provide re-skilling solution for existing developpees facing difficulties in finalizing their full integration to operational staff by developing a pre-program.

Further to the development of technical competence, the new program strives to contribute to the development of mature and responsible attitudes amongst our graduates, in view of a successful integration within ADNOC workforce. The first trainees will graduate in March 2019 and will integrate ADNOC Group Companies (GCs).

A priority is finalizing the work of the Assessment and Competency Development Centre in identifying the competency gaps of existing operators and technicians and addressing them through proper solutions.

ATA is working now to maximize its intake capacity and deliver 600 graduates per year as well as getting the program accredited to the diploma level.
Risk Mitigation for Further Development of a Mature Field through Multiple Parameter Sensitivity Study
Authors: Yamada Tatsuya , Yamamoto Kei , Alqubaisi Alyazia , Al Jasmi Sami , Uematsu Hiroshi , Kojima Keitaro , Shibasaki Toshiaki , Al-Jenaibi Faisal
Published: November 2018

Reservoir simulation is widely used for field development planning in many fields and the evaluation of uncertainty range in production forecast is indispensable to make decision for further investment. Reservoir simulation model consists of geological, petrophysical and reservoir engineering parameters for each cell and cell boundary. These reservoir model parameters are usually defined based on limited available data in consideration of their uncertainty range. Therefore, the identification of influential parameters and the reduction of uncertainty range for these parameters are key components to mitigate the prediction uncertainty.

An Upper Jurassic carbonate reservoir in Field A located in offshore Abu Dhabi has long production history for more than 30 years. Field A experienced several development schemes including natural depletion, crestal gas injection and crestal water injection. The current reservoir simulation model reasonably replicates historical performance on pressure, water cut evolution and GOR trend in field and well-by-well scales. On the other hand, we identified some reservoir model parameters have high uncertainty due to reservoir complexity and lack of reliable data.

In this study, we focused on the identification of influential parameters on production forecast and the reduction of parameter uncertainty range using an experimental design approach. More than 200 simulation cases were generated with different combination of selected parameters using Latin Hypercube Sampling method. In each case, we evaluated history matching quality in field scale and relationship between history matching quality and each parameter. We found some parameters have correlation with history matching quality independently from the other parameters settings. This means that the uncertain range of those parameters can be reduced to achieve an acceptable history match irrespective of the other parameters. Furthermore, the prediction uncertain range was analyzed using the selected cases showing reasonable history matching quality to investigate the relationship between cumulative oil production and each parameter. The results indicated some parameters have a stronger impact on production forecast and their uncertainty range need to be reduced by further data gathering or considering other mitigation plans. This study successfully demonstrated that the proposed multiple parameter sensitivity analysis by effective use of experimental design approach enables to reduce the parameter uncertain range and identify the key influential parameters. Furthermore, this study result contributes to the prioritization and optimization of future data gathering plan in Field A.
Wireline Cable Protection: Enabling Fluid Sampling in High-Risk Wellbores
Authors: Wheater Guy , Huyton Stuart , Miller Luke , Gerrity Russel , Ford Ronald
Published: November 2018

Wireline cable sticking is most frequently experienced during formation fluid sampling. In this situation, if the cable cannot be freed, strip-over fishing is the only remedy; this is a cost and risk-intensive activity which may extend the logging job by several days and result in further inefficiencies such as wiper trips or pipe-conveyed logging to fully satisfy the formation evaluation objectives. In this paper, the authors outline a proven engineering approach that permits the systematic identification of high-risk wells for cable sticking, where the deployment of wireline standoffs (WLSOs) may facilitate safe and efficient sampling on wireline.

The precursor of all cable sticking is slot cutting into mud-cake or formation. The slot is generated by sustained lateral pressure from the moving (tensioned) logging cable, referred to hereafter as "cable thrusts". A sophisticated 3D cable force model evaluates the cable contact zones and thrusts along the open hole section under analysis. For differential sticking, a cable contact and sticking limit in mud-cake is computed, having adjusted the pore pressures to offset data. For keyseating, the well is benchmarked against wells with similar trajectories, gained from a global study on cable sticking. Sticking-linkage is also assessed, whereby overpulls from tool sticking may induce cable sticking, via amplified cable thrusts against mud-cake or formation. To reduce cable sticking risks to an acceptably low level an array of WLSOs may be deployed, combined with optimised logging procedures and winch techniques.

Operators are now employing this approach on a regular basis as an important risk management tool, from the well planning stage through to completion. WLSOs have been successfully deployed for 40 sampling runs on 25 wells, in fields with a history of severe cable sticking or fishing. Prior signs of sticking have largely been eliminated, resulting in significantly reduced well costs, whilst avoiding pipe-conveyed logging or LWD, and without consideration to the value of lost data or samples. Well Engineering may now use this approach to design and optimize ambitious well trajectories, potentially saving a hole section, in the full knowledge that future wireline fluid sampling can be performed within the bounds of acceptable risk. Real-time risk assessments have proven invaluable, to track the risk trend as the well is drilled, leading to a final decision on the requirement for WLSOs, with additional optimisation of the sampling procedures if needed.

Operational best practices and lessons learned are summarized, as well as an outline for future R&D to understand and reduce wireline conveyance risks even further.
Installation of Reinforced Thermoplastic Pipe RTP as Permanent Gas Flowline
Authors: Al-Khabrani Mohammad A. , Parvez Anwar
Published: November 2018

Reinforced Thermoplastic Pipe (RTP) is a new technology that is reducing the cost of constructing oil and gas pipelines while improving reliability. RTP combines high performing materials such as bimodal high density polyethylene with high strength reinforcing fibers in a unique construction to create a high pressure pipeline system. RTP is corrosion-resistance component that require low maintenance and more cost effective compared to carbon steel. It will enhance the pipeline integrity and will open windows for corrosion inhibitor optimization in the system.

RTP has already been executed for the first time in Saudi Aramco for permeant natural gas transporting pipeline with elevated pressure and temperature parameters. The first application has already been installed at Southern Area Gas Producing Department (SAGPD) in a candidate gas well to pilot the installation and measure the performance of the 6″ RTP flowline for six months.

The primary benefit of RTP is realized by the installation methodologies available which contribute overall project savings of up to 30-50% for typical gas applications. Additional installation benefits include reduced right of way requirements, reduced safety hazards, and reduced environmental impact. Consequently, the utilization of RTP for new gas wells tie-in will significantly contribute in huge cost saving considering the high number of forecasted gas wells in the coming few years.

The main objective of this technical paper is to give an overview on the recent implementation of RTP pipe for the first time in sweet gas services applications in term of constructability and suitability.
Investigation of Smart Water Flooding in Sandstone Reservoirs: Experimental and Simulation Study Part2
Authors: Al-Saedi Hasan, N. , Flori Ralph E. , Mortadha Alsaba
Published: November 2018

In this paper, we considered the effect of water chemistry on water-rock interactions during seawater and smart water flooding of reservoir sandstone cores containing heavy oil. Oil recovery, surface reactivity tests, and multicomponent reactive transport simulation using CrunchFlow were conducted to better understand smart water flooding.

Secondary water flooding with FW at 25°C resulted in an ultimate oil recovery (UOR) of ~50% OOIP for all reservoir cores in this study. Formation water salinity was 104,550 ppm. FW was diluted twice to obtain SMW1. SMW2 was similar to SMW1 but depleted in divalent cations (Ca2+ and Mg2+). SMW3 was also similar to SMW1 but depleted in Mg2+ and SO42-, while SMW4 was the same as SMW1 but Ca2+ was diluted 100 times. Seawater salinity was 48300 ppm, which is close to the smart waters salinity (52275 ppm). No oil recovery was observed during SMW1 flooding, while softening SMW1 (SMW2) resulted in a significant additional oil recovery OOIP. Depleting Mg2+ and SO42- resulted in additional oil recovery but smaller than in SMW2. Diluting Ca2+ 100 times was the second best scenario coming after depleted Ca2+ in SMW2. The results of this study showed that the more diluted Ca2+ is in the injected brine, the more additional oil recovery that can be obtained, even though the other divalent/monovalent cations/anions were increased or decreased or even depleted.

Other reservoir cores were allocated for surface reactivity test. The absence of an oil phase allows us to isolate the important water-rock reactions. The Ca2+, Mg2+, and SO42- effluents for all cores were matched using CrunchFlow, and then further investigations of the water-rock interactions were conducted. The reactive transport model showed that decreasing the Mg2+ concentration will decrease the number of the most effective kaolinite edges Si-O- and Al-O-, but was not as pronounced as that in present of Ca2+, which explains why lowering Mg2+ concentration gives lower additional oil recovery, and why lowering Ca2+ concentration gives higher additional oil recovery.
Complex Reservoirs Characterisation Technique Based on Geological Seismic Conditioning and its Application in a Oilfield, Middle East
Authors: Xin C. , Zhaowei L. , Zhaofeng W. , Wenyuan T. , Yaliang X. , Yanjing L. , Xiaodong W. , Hongmei W. , Yu J. , Xiaohuan Y.
Published: November 2018

In order to improve the accuracy of reservoir prediction results, the conventional method usually include seismic inversion, and wei. Due to the limitation of the vertical resolution of seismic data, it is hard to identify the thin reservoir by seismic attributes directly. In order to improve the prediction accuracy of reservoir, this paper show a new reservoir characterization technique based on geological seismic conditioning. The new method mainly includes five steps. The first step is sedimentary facies classification based on the geological seismic analysis, such as core data, thin section analysis, FMI logging, NMR logging and conventional logging. The second step is modern sedimentary model optimization and forward modelling. In order to establish a reasonable sedimentary facies model, a similar barrier island modern sedimentary model was chose. To understand the geological significance of seismic data, two different dominant frequency were designed for forward modelling based on the sedimentary facies model and petrophysical analysis. The third step is seismic conditioning under the guide of sedimentary facies model forward modelling. The next step is seismic constraint stochastic inversion, and the last step is reservoir characterization and new well confirm. The application of this method in A oilfield shows that the techniques not only improved the identification ability of the reprocessing seismic data, but also improved the prediction accuracy of the reservoir characterization results. This new reservoir characterization technique can integrated multidisplinary information, such as modern sedimentary model, well data and seismic data, to establish a reasonable sedimentary model, to enhance the resolution of seismic data by conditioning, and get an reasonable reservoir characterization results based on the seismic inversion.
Rootzone for Oil Treatment and Recirculation
Authors: Løgstrup Jørgen
Published: November 2018

Transform has over the last 30years set up several projects for treating oil contaminated water and sludge. Special attention has been to treat and recirculate wastewater from car, container and train wash. With this experience it was decided to test and acquire an EU Environmental Technology Verification. Result of this test is that the specific developed Rootzone soil filter can adapt and decompose oil contaminant. It is documented that the treated water can be recirculated or reused for irrigation or other purposes. Approval from EU was given on the 9th of January 2018, as the first and only approval by EU of treating oil contamination. This presentation is the first given since approval.
Piloting Elastomeric Wraps for Protection of Offshore Boat Landing
Authors: Alshammari Sattam , Salazar Vidal Oscar Daniel
Published: November 2018

The scope of this paper is to describe the advantages of utilizing Elastomeric Wraps for repairing and protecting offshore boat landing piles located in the splash-zone, which is a challenge worldwide, and to make comparison between this new protective Wraps and our existing repair practice. With the aim to improve the capabilities of the boat landing to absorb impact energy by approaching vessels without structural failures and to enhance corrosion resistance at the boat landing piles. Currently, Safaniyah Offshore Department repairs corroded boat landings piles by welding half sleeves pipes to restore the thickness of the boat landing structured piles and then applying anti-corrosion coatings. This practice consumes significant execution time, requires hot working activities [e.g. welding] and has a limited durability [e.g. most boat landings require costly refurbishments and repairs every 3 to 5 years intervals]. Furthermore, most of offshore platforms have boat landings, which consume significant offshore maintenance resources [e.g. boats and barges time] to conduct necessary repairs for eliminating further damages to the platform structures. Due to these challenges, Elastomeric Wraps, induced-tension polymer Wraps, was piloted at a high traffic boat landing to test its capability to pass pre-determined success criteria, which include significant reduction in corrosion rates and higher level of boat impact resistance. The advantages of this design include cost saving, faster installation time, better maintainability, longer life service, improved anti-corrosion protection, higher resistance to boat impact and safe installation (no hot work required). The Elastomeric Wrap was installed in 2017 at a boat landing for the first time as part of the efforts to provide a permanent solution for protecting the splash-zone piles located in a very corrosive environment, and subject to potential mechanical damage from repetitive impacts by approaching vessels. This product is not only designed to mitigate the corrosion effects, it also protects against mechanical impacts at boat landings by Marine vessels [e.g. supply boats, maintenance barges]. The design also can be modified in the field as per specific-site requirements and dimensions, which provides additional flexibility for field maintenance. The rigorous criteria for considering the Wrap as a successful alternative are aimed at identifying area of deficiencies in the design stage during field trials and before approving the Wrap for maintenance of the boat landing. In short, the Elastomeric Wraps is developed for maintaining assets integrity, ensuring efficient utilization of company's valuable resources and safe operation for transferred personnel, crew vessels and supply boats, which is in line with Aramco Operational Excellence (OE) and Safety Management System (SMS) objectives.
Clair Phase 1: The Evolving Development of a Complex Fractured Field
Authors: Webster Mark
Published: November 2018

The Clair field is the largest discovered oilfield on the UK continental shelf (UKCS) but has high reservoir uncertainty associated with a complex natural fracture network. The field area covers over 200 sq km with an estimated STOIIP of 7 billion barrels. The scale and complexity of the reservoir has led to a phased multi-platform development.

Phase 1 started production in 2005 with 20 wells drilled prior to an extended drill break. Five new wells (A21 to A25) were drilled and brought online during 2016/17 which increased platform production by c.70%. The new wells incorporated historic lessons to mitigate the risk of wellbore instability in the overburden and be robust to the dynamic uncertainties of the fractured reservoir. Many of the well outcomes and risk events were predicted and mitigated effectively, however the new wells still provided some surprises.

This paper presents a summary of the lessons from the historic Clair development wells which underpinned the recent drilling campaign and additional field understanding provided by the new well results. New insights include a narrower overburden drilling window and zonal isolation challenges within the reservoir.
Use of FIDIC 2017 as Standard Form of Contract for EPC Projects in Oil and Gas Industry
Authors: Bidua Abhishek Kumar
Published: November 2018

Standard form of Contract for Engineering, Procurement and Construction (EPC) Projects in Oil and Gas industry has not gained the favor. Most of the NOCs/IOCs (National Oil Companies / International Oil Companies) prefer to use standalone bespoke EPC Contracts often based on in-house expertise that is developed from using the contents of different standard forms of Contract. This requires a lot of care during the drafting and several rounds of lengthy instructive discussions during the tendering. This paper discusses whether the use of Second Edition of FIDIC Form of Silver Book or Yellow Book released in December 2017 is possible as acceptable standard form of Contract for Oil and Gas Industry with the use of Particular condition to address the special requirements of a Project.

The EPC Contracts for onshore and offshore oil and gas projects are generally experiences the issues related to deficient scope definition, force majeure, performance related issues, indemnity, insurance provisions, change orders, termination, limitation of liability, no damage for delay etc. Second edition of FIDIC rainbow suite has striven hard to address the above stated issues with balance distribution of the risk.

The 2017 FIDIC Form of Contracts provides increased reciprocity between the Parties (i.e. Employer and Contractor) with an emphasis on notices and time bar provisions. Further, use of standard form of contracts such as FIDIC facilitates better understanding of the risks distribution at the outset of contract due to availability of precedence and accepted explanation of ‘terms and conditions of Contract’.
Evaluation of Gel Treatment in Fractured Reservoir Using Embedded Discrete Fracture Model: Experimental and Simulation Investigation
Authors: Alhuraishawy Ali K. , Wei Mingzhen , Alsubaih Ahmed A. , Bai Baojun , Almansour Abdullah
Published: November 2018

Preformed Particle Gel (PPG) have been used as conformance control in mature oil field. Reservoirs ith fractures and very high permeability are candidates for gel treatment. By injecting the PPG in the flooded area, the post waterflooding reached unswept area and improve oil recovery factor. Recently, Discrete Fracture Model (DFM) has been reached a great attention by some researchers in reservoir modeling area. Therefor, DFM was used to evaluation of gel treatment in fractured reservoirs using different senarios.

Outcrop carbonate core with oil-wet wettability was used to establish the experiment part. Transparent acrylic plates was used to design the fracrure model with 1.5 mm fracture width. Sodium chloride was prepared for waterflooding and PPG swollen. The experimental results showed that the preformed particle gel improved the oil recovery improved by 12% after gel treatment with 20% water cut reduction as an experimental results. Morover, the experimental result showed a very good match with simulation results in lab scale. The main PPG design variables are PPG concentration and PPG treatment timing according to the field scale simulation resuls and when gel treatment applied early, the oil recovery improved. The integration of gel treatment and Embedded Discrete Fracture Modeling (EDFM) will help the field developers to select the best senario for gel treatment.
Oil Gain from Successful Water Shut-Off Strategy
Authors: Ghatrifi Suhaib , Sulaimi Ghadna , Jimenez Chavez Maria , Sivrikoz Ayca
Published: November 2018

Water Shut-Off (WSO) actions are remedial activities that are being implemented in the heavy oil N Field, with the objective of reducing the water inflow of the well by closing zones which are major contributor to the high water cut. WSO are commonly executed as a mitigation action in operating wells with previous economic value. The purpose of this study is to develop a thorough knowledge of the rate of success of WSO activities linked to the time of WSO implementation, type of well (either horizontal or vertical) and the presence or lack of PLT (Production Log Test).

Success was evaluated by reviewing the net oil production rate before and after WSO activity with the gained net oil rate being converted to US Dollars.

There is no significant difference found in the success ratios between horizontal wells and verticals. However, in the horizontal wells, 74% of the successful ones were the heel shut-offs. WSO activities are found to have a success rate of 100% if the activity is implemented within the first year of the start of high water cut. Moreover, wells with WSO implementation within the first three years of observing high water-cut have a success rate of 65%. Noticeably, the success rate decreased dramatically with time, with wells having high water-cut for seven years and up to eleven years to the time of WSO implementation. These wells show success rates of 50% and 33% for seven and eleven years respectively.

A numerical sector model and well model were created to explain these findings. During oil production because of a localized decrease in pressure, the water-oil interface may rise up and deform into a conical shape near the well. This phenomenon is known as ‘water coning’. At the time of water breakthrough, the cone is observed to be narrower than more advanced stages when the water cut has risen to higher levels. At these times, the cone has broadened and, depending on spacing between adjacent wells, has lifted the overall level of the oil/water interface, decreasing the distance between the wellbore and the water. As a result, water shutoff becomes less effective with time.

It is recommended to start WSO activities on wells within the first three years of high water-cut indications. In case there is no PLT or other data, heel shutoff for the horizontal wells have a better success rate.
Optimized Isochronal Flow Tests
Authors: Franco Francy , Rincon Alexander , Useche Marcos
Published: November 2018

An Optimized Isochronal Test (OIT) is presented to evaluate the deliverability of a reservoir eliminating the need of shut-in periods during a multirate well test, which represents an operational constraint for classical isochronal tests and in some instances for modified isochronal tests.

The proposed technique is based on the effect of several consecutive and different production rates over the well-reservoir model during both transient flow and pseudo-steady state flow; thus, it is possible to estimate the reservoir pressure at different radius of investigation, and the ratio between production volume and pressure drop. This method does not require stabilization of static reservoir pressure after a flowing period since it is calculated using a mathematical procedure based on the transient pressure equation.

A reservoir simulation model with known petrophysical parameters, fluid properties, pressure and temperature, is used as a reference to evaluate the accuracy of the proposed methodology. Two types of fluids are tested, a low compressible black oil and a high compressible gas condensate, with the objective to demonstrate the optimized isochronal test applicability with pressure, pressure squared P^2, and pseudo-pressure Ψ(P) equations. The production deliverability is evaluated applying four different analysis: flow after flow test, isochronal flow test, modified isochronal flow test and the proposed optimized isochronal flow test; the results are compared and analyzed using the percentage of error found for every method.

The optimized isochronal analysis provides the option to avoid shut-in periods during a multipoint well test and provide reliable production deliverability curves. OIT has a direct impact in reduction of costs and deferred production for companies involved in oil and gas operations.
Take a Closer Look to Maximize Energy Savings
Authors: Nambakkam Harindranath , Al Jenaibi Eisa Salem , Sajjad Saqib , Al Sayegh Farah
Published: November 2018

Comprehensive Energy studies entices in identifying potential energy savings in gas processing industry.

The approach is to study, measure, analyze and quantify: Current energy situations with regards to processes and equipment operations;Sources or areas of energy losses in processes and equipment;Productive use of waste heat/energy;Alternative (cost-effective) energy substitutes;Modalities for augmenting energy losses and energy wastage in processes and plant equipmentMeasures which do not require large investments, but can lead to 8 to 10 percent savings in energy consumption.

The Comprehensive Energy study has resulted in the identification of 31 potential energy saving opportunities, which could allow the company to achieve expected savings of up to 20%. Out of thirty one savings opportunities, seven were identified as potential quick wins with 10% saving potential, eight opportunities would require further analysis and investigation and sixteen opportunities were kept in abeyance due to economic factors. Quick wins, such as: Review of Advanced Process Control (APC), Sniffer Valve Leakage Survey, Plant wide control tuning, Efficiency check on LP and Residue gas Compressors, HP Feed gas discharge pressure control and Propane compressors Desuper heater Fan Controls which contributed to 10% energy savings were identified during the study. Payback periods are very attractive, in the range of 3 months, for these quick wins.
Cleaning and Retrieval of Spilled Crude Oil and its Application as a Refinery Feedstock Using Highly Efficient Polymeric Nanofibrous Sorbents
Authors: Alnaqbi Mohamed , Alblooshi Afra , Greish Yaser
Published: November 2018

Objectives/Scope

The objectives of this project are to develop novel and more efficient materials to be used as sorbents for crude oil spills and to explore their potential for retrieval.

Methods, Procedures, Process

A number of remedies have been explored for the collection of spilled crude oil, which is one of the major environmental problems. Sorbents of different forms are being used as one of these remedies. However, adsorbed oil spill and used sorbents provide a secondary source of pollution. In our laboratories, we have developed polymeric nanofibrous sorbents that showed a high affinity towards the sorption of spilled crude oil. Moreover, the water-free adsorbed oil as well as the used sorbent were completely recycled into a homogenous solution that can be added to the refinery feedstock.

Results, Observations, Conclusions

Polymeric materials of various origins were converted into micro- and nanofibrous sorbents using a novel nanotechnology approach. Those fibers are characterized by their high surface area, and interconnected porosities. The homogeneity of the fiber size and pore size distributions was optimized in order to maintain a high degree of reproducibility. Fibrous sorbents were therefor applied to crude oil spills that were intentionally made over a simulated sea water medium. Results showed that sorption of the crude oil spill started within seconds of contact between the fibrous sorbent and the spilled oil. The water-free adsorbed oil showed a sorption capacity of up to 217 g/g of the fibrous sorbent. Moreover, the adsorbed oil as well as the used fibrous sorbent were completely converted to a homogeneous solution that can be directly forwarded as a feedstock to the refinery, hence provide a high economic value of retrieving the spilled oil and minimizing secondary sources of pollution.

Novel/Additive Information

The current approach is solely developed and tested in our laboratories and provides a more efficient approach to the cleanup and retrieval of crude oil spills from aqueous media. Our sorbents are competitively less expensive than those imported with a higher sorption efficiency. Moreover, our approach provides an additional solution to spilled oil and used sorbents through their recycling and re-use in the refinery feedstock.
Seismic Inversion and Tectonostratigraphy Integration in the Reservoir Model: A Case Study of Giant Carbonate Reservoir Characterization and Modeling, Onshore Abu Dhabi
Authors: Latief Agus Izudin , Syofyan Syofvas , Grover Anurag , Ali Shabibi Tariq
Published: November 2018

The carbonate reservoir properties distribution can be completely different from what expected of the depositional framework. The subsequent diagenesis processes, often multi stages, commonly overprint the primary porosity-permeability system. Therefore, comprehensive understanding of both depositional and diagenesis processes is very crucial to produce robust reservoir model.

In the case of mature field development with abundant data availability, reservoir modeling should be more data driven and integrate multi-discipline observation and understanding. The objective is to yield less-subjective and data-consistent model with better prediction quality. However, the understanding of geological processes governing reservoir heterogeneity shall be made as foundation in all cases.

The case study discusses on how a comprehensive multi-discipline review unravels and presents a completely new reservoir heterogeneity framework. Diagenesis processes were investigated from both burial and tectonic evolution/ tectonostratigraphy perspective. The 3D reservoir rock type framework as net product of deposition and diagenesis process is created by combining well vertical heterogeneity and seismic lateral information into 3D trend model.

The integrated and data-driven modeling approach reconciles process origin and the resulted reservoir heterogeneity. The inclusion of tectonostratigraphy component leads to better prediction result. Multi-disciplines integration provides an interpretation corridor, hence minimizing error due to subjectivity and/or limited level of experience.

The newly built reservoir model serves as basis for development plan optimization in the respective reservoir. The drilling result of some recently drilled wells shows a very good consistency with model prediction.
Alternative Method for Pressure Transient Analysis
Authors: Franco Francy , Rincon Alexander , Useche Marcos
Published: November 2018

An alternative method is presented for estimation of reservoir properties that are usually estimated in a classic buildup test are obtained using flowing conditions thereby eliminating the need for shut-in periods and measurement of static pressure data.

The proposed approach is based on the effect of two consecutive periods of production with different rates in a single well-reservoir model. The well is initially produced at a constant rate until pseudo-steady state conditions are reached, followed by a different rate that will generate a pressure transient response measured at bottom of the wellbore. A mathematical formulation is applied to estimate the reservoir pressure as function of radius of investigation, which is equal to the bottom hole pressure observed during a shut-in buildup test.

A single well-reservoir model with known petrophysical parameters, fluid properties, pressure and temperature is used as a reference to evaluate the proposed methodology. The reservoir (i.e. the simulation model) is tested by applying two methods: the first one, is the simulation of a classic buildup test, and the second one, is the simulation of two flow rates periods according to the new theory; the results are compared with the model of reference, calculating percentage of error for permeability, skin, and average reservoir pressure. Additionally, it is demonstrated that a shut-in period is not required to obtain data equivalent to a classic buildup test since it is possible to calculate it from dynamic behavior.

The ability to complete a well pressure transient analysis test from flowing conditions and provide valid and reliable results has a direct impact in reduction of cost and deferred production for companies involved in oil and gas operations.
A Study on the Effect of Biological Processes on Trapping Mechanisms and Storage Capacity for High Temperature Depleted Gas Field
Authors: Mohd Amin Sharidah
Published: November 2018

One of the most secure storage sites for CO2 injection is in depleted gas reservoirs. To ensure that the CO2 is trapped securely and will not escape to the surface, storage in such formations must be study carefully prior to injection in such formations. After the injection, the injected CO2 will undergo several trapping mechanisms; namely: hydrodynamic, solubility and mineral trapping. The extend of geochemical reactions involved depend on the composition of the injected fluid introduced in the aquifer, the composition of the initial minerals assemblage and the aquifer brine. In this paper, the importance of biological/microbial mechanisms towards the impact on the storage capacity was studied using reactive transport modelling. The results obtained shows that the presence of microbial compound such as organic matter contributes to the enhancement of mineral precipitation, resulting in secure long-term storage.
Mud Losses Estimation Using Partial Least Squares Algorithm
Authors: Al-Hameedi Abo Taleb , Alkinani Husam H. , Dunn-Norman Shari , Flori Ralph E. , Hilgedick Steven A. , Alsaba Mortadha T. , Amer Ahmed S.
Published: November 2018

Lost circulation is a very expensive drilling problem and very common in highly permeable formations, fractured formations or depleted reservoirs. Estimates of annual cost worldwide for lost circulation are over a billion for lost time and materials, and remediation costs. The drilling industry has a large toolbox from which to customize lost circulation responses. However, putting a value on the effectiveness of these lost circulation mitigation methods is harder to quantify.

The Rumaila field, Iraq, is one of the world's largest oilfields with overlying formations that are notorious for lost circulation issues as the formations are depleted, highly permeable and fractured. Because of the significance of the Rumaila field and the common lost circulation problems faced in drilling any well in the area, it is an ideal candidate for a statistical study to model anticipated mud losses and compare the model with actual mud losses. The resulting model should be able to predict average mud losses, along with other drilling parameters affecting lost circulation, and compare the different lost circulation methods used to mitigate known losses.

This study provides a larger data set and different models, using a machine learning algorithm than previous studies in the Rumaila field. Data of key drilling parameters for more than 500 wells are gathered from daily drilling reports, technical reports, final wells reports, and drilling programs. Sensitivity analysis identified the most critical parameters and provides insight into the impact of those parameters on mitigating lost circulation. The models of mud loss, equivalent circulating density (ECD) and drilling rate (ROP) are then tested with new data and compared with previous regression models developed for the area.

Using the same techniques, modeling of any formation can be used to analyze the current situation and develop techniques for mitigating lost circulation by controlling drilling fluid properties, the rate of penetration, response to lost circulation events, and other field parameters.
Digital Rock Physics Combined with Machine Learning for Rock Mechanical Properties Characterization
Authors: Saad Bilal , Negara Ardi , Syed Ali Shujath
Published: November 2018

Rock mechanical properties is essential for several geomechanical applications such as wellbore stability analysis, hydraulic fracturing design, and sand production management. These are often reliably determined from laboratory tests by using cores extracted from wells under simulated reservoir conditions. Unfortunately, most wells have limited core data. On the other hand, wells typically have log data, which can be used to extend the knowledge of core-based mechanical properties to the entire field. Core to log integration of rock mechanical properties and its interpretation is limited by our current understanding of rock physics. The gap is clearly evident where approximations such as empirical relationship between dynamic and static mechanical properties are used for rock failure estimation. This paper presents a hybrid framework that combines advances in digital rock physics (DRP) and machine learning (ML) to predict rock mechanical propertiy (e.g., Young's modulus) from rock mineralogy and texture to improve the accuracy of mechanical properties determined from log data.

In this study, mineralogy, density, and porosity data are obtained from routine core analysis and rock mechanical property from triaxial compression tests. In our methodology, we utilized DRP models which were calibrated against core data and then generate rock mechanical property, for intervals for which triaxial measurements were not available. Mineralogy and texture data are used to create DRP models by numerically simulating rock-forming geological process including sedimentation, compaction, and cementation. Rock mechanical properties derived from DRP are used to enhance the set of training data for the ML algorithm to establish a correlation between rock mineralogy, texture, and mechanical property and construct the ML-based rock mechanical property model. The ML model generates Young's modulus predictions and are compared with the laboratory measurements.

The predicted Young's modulus of rock models from the combined approach has a good agreement with the laboratory measurements. Two quantitative measures for estimation accuracy are calculated and examined including the correlation coefficient and the mean absolute percentage error. Cross-correlation plots between the Young's modulus predicted from the ML model and experimental results show high correlation coefficients and small error. The results of the study show that DRP model can be used to feed the ML model with reliable data so that the prediction accuracy can be improved. The results of this work will provide an avenue of learning from the formation lithology and using the knowledge to predict rock mechanical properties.
Integrated Analysis and Optimization for Progressing Cavity Pump Systems in Greater Burgan Field
Authors: Najaf A. A. , Ramchandra A. , Al-Yetama M. , Ledesma F. , Al-Salman A. , Suleiman N.
Published: November 2018

Progressing cavity pump (PCP) systems are widely used in the oil and gas industry. Continuously evaluating PCP performance helps to maximize and sustain fluid production and increase pump run-life. This paper focuses on integrating a real-time platform and advanced software to model, troubleshoot, and optimize PCP systems and their operation.

More than 50% of installed PCP systems located in Great Burgan Field in southeast Kuwait are connected to a real-time SCADA platform. These connected systems are monitored to support daily operations and to identify underperforming wells for troubleshooting. Special attention is given to wells exhibiting critical behaviors or wells with optimization opportunities. Before implementing any actions on these wells, real-time data history is used along with nodal analysis to predict the outcomes. This paper presents an intensive optimization analysis through the following field case studies: Preventing sucker rod string failureEvaluating pump submergenceOptimizing fluid productionIdentifying optimum operating conditions

Software is used to perform simulations of flow under different operating conditions and to generate a full analysis report based on PCP equipment configured in the well model. The sharp-edge results are not limited to the production rate. They also extend to pump performance and other surface and downhole parameters such as pump torque, intake pressure, and discharge pressure. The outcome of these results assists with making well-informed decisions with the following benefits: Operating conditions have been improved by estimating the production rate at different speeds.Pump life has been improved by evaluating rod load, lift load, and efficiency.Down-time has been reduced by preventing pump-off conditions.

The procedure serves as a proven guide for analysis and optimization of PCP systems. Improving pump efficiency, achieving the target production rate, identifying problems, and preventing potential failures all help to optimize PCP system performance.

The innovative integration of PCP analysis and optimization provides a means to increase production and reduce the load percentage of surface and subsurface equipment parameters. A real-time SCADA platform combined with the optimization software created an ideal solution to keep wells operating at peak performance levels.
A Case Study from a 53 Year Old Asset - The Importance of Integrity and Risk Management for a Mature Asset
Authors: Jadoon Ammer
Published: November 2018

BP is a joint venture partner in GUPCO, which operates in the Gulf of Suez, Egypt. The asset is over 50 years old and has a large operational foot print. This includes 3 onshore process facilities handling over 450,000 barrels of fluid per day from over 100 offshore structures and 200 pipelines. The field is supported by gas lift and water injection from two onshore facilities.

The asset presents a challenge from an integrity perspective, namely corrosion and production chemistry threats. These are managed through an inspection program and anomaly management process.

This case study presents how our asset integrity is managed and forward plan for improvement. The important relationship with the risk management process is highlighted.
Thinking Differently Ensures Integrity of Fire Water Network
Authors: Qamar Shahid , Al Maskari Juma , Narayana Sathyanath , Nath Nahum Kant , Rafiq Shahid , Albraiki Ahmed
Published: November 2018

With focus on enhancing Integrity and efficiency, ADNOC Gas Processing identified an opportunity for optimization of existing FRP firewater system in Ruwais. A comprehensive study of complete firewater network and review of operating and control philosophy performed in order to optimize the system performance and mitigate pressure surge problems. This paper presents measures that ADNOC Gas Processing have adopted to achieve improved system efficiency and lower operating cost.

A study was undertaken by GASCO to review issues with existing Fire Water network (FWN) at Ruwais to enhance overall performance of system in terms of design, operation and control. Initiative was to identify problems, evaluate root cause and think of optimization including some cost saving solutions. Study explored various operating configurations of existing 4-working+ 4-standby pumps with active involvement of operation personnel followed by hydraulic and surge analysis with different operating scenarios. Study revealed reduction in flow, head and pressure to mitigate fire water piping surge problems. Study also engaged pump vendors to establish feasibility of modifying the existing pumps.

The study identified that each existing fire water pump is suitable to deliver 1400 m3/hr against required flow of 1000 m3/hr. Additional flow may create pressure spikes and surges in FWN. Hydraulic analysis found that pressure was above minimum requirement of 7bar (g) at the most remote point in network. Simulation indicated that fluid velocity was above 3.5 m/s at specific sections on the ring main. Increase in pipe sizes is required to arrest velocity within recommended limit in these areas. Option of lowering the operating pressure of main fire water pumps without the fire water network pressure falling below 7bar (g) at the most hydraulically remote point in the network was studied. Also the option of 3W+3S and 4W+4S [working (W) and standby(S)] pumping configuration was studied so as to establish that system can work with less number of pumps. Hydraulic study concluded that rated pressure should be reduced along with shut-off pressure. The maximum worst case fire water demand is 3200 m3/hr. The demand is found to be achieved with three Fire Water Pumps. During study pump vendors were engaged to arrive at the conclusion that 3W+3S configurations are hydraulically acceptable with pump / impeller modifications and de-staging options.