bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving the Operation Performance Along With Production Profiles in Tight Basement Oil Reservoirs by Utilizing Ball Drop System of Multi Stage Hydraulic Fracturing
Authors: Kortam Mostafa , Zayed Samir , Conrad Joel , Ezeldin Saiff , Batmaz Taner
Published: November 2019

Increased production alongside low costs has always been a long-standing goal for operators in a time where the industry is thriving to increase their operational and economical efficiencies. For maturing fields, operators are constantly seeking innovative techniques to access large quantities of reserves found in low permeability formations.

The nature of the reservoir has resulted in an economical need to implement a hydraulic fracturing campaign. This would assist with increased production through wider contact area of the producing interval. After a campaign resulting in favorable results through hydraulic fracturing, additional efficiencies addressing the operational and cost concerns of cemented plug & perf were required. In order to maintain production increases while maintaining operational efficiency, the need for multi-stage hydraulic fracturing became evident.

Six candidate wells were selected for proppant fracturing utilizing a multi-stage completion technique that has been widely adopted in North America for the past 17 years and internationally for over a decade. The technique utilizes a series of hydraulic mechanical packers and fracturing ports that are shifted open sequentially across the applicable zones targeted for treatment. The ports have seats that are sized to respective balls, which are used to isolate the stimulated intervals. The system allows for increased efficiency through eliminating the risks associated with wireline operations for perforating, or coiled tubing operations to mill out bridge plugs. It also allows for immediate and simultaneous production from all stages as well as contingencies for shutting off water zones. From June 2016 to March 2017, six systems were installed consisting of 6 to 8 hydraulic fracturing stages, which were placed in cased-hole pre-perforated wells.

This paper investigates reservoir quality assessment as well as the stimulation efficiency and productivity enhancement of the Sidri Field. It investigates two different completion methodologies to investigate operational efficiency and productivity enhancement of the Sidri Field in the Sinai Peninsula. The comprehensive evaluation will involve discussions of candidate selection, pre-job design alongside comparisons of timeline, cost, zonal isolation, and productivity to help serve as a guideline for operators in the region looking to enhance their completion approach.
CO2 Capture From Natural Gas Combined Cycle Power Generation Using Carbonate Fuel Cells
Authors: Kiss Gabor , Barckholtz Timothy A. , Blanco Gutierrez Rodrigo F. , Han Lu , O'Neill Brandon , Rosen Jonathan , Sutton Clay R. , Davis Keith E. , Dobek Frank , Geary Timothy , Ghezel-Ayagh Hossein , Jolly Stephen , Willman Carl
Published: November 2019

Electrical power generation facilities account for a large share of global CO2 emissions. Because they are stationary single-point emitters, power plants are an obvious target for reducing anthropogenic CO2 emissions by CO2 capture. Capture from Natural Gas Combined Cycle (NGCC) power generation has been much less investigated than from coal power generation, despite having approximately half of the CO2 emissions per electrical unity of energy produced as compared to coal-fired power plants. Furthermore, the majority of carbon capture R&D has been devoted to the development of amine scrubbers, a process which incurs a significant energy debit because of its steam consumption in the sorbent regeneration step. Molten Carbonate Fuel Cells (MCFCs) can be used for CO2 capture from NGCC facilities without a significant energy debit. They are modular, thus flexible in fitting the required capture capacity. When using MCFCs for carbon capture, additional power is created by the fuel cells keeping the total efficiency of the power generation system at or near the efficiency of the NGCC plant without CO2 abatement.

This paper summarizes the current status of MCFC carbon capture technology for low-CO2 emission abatement. We developed modeling tools and performed process simulations to optimize MCFC performance and to develop and assess integrated solutions for power generation with carbon capture. We also obtained proof-of-principle data at the bench scale, using small button cells and lab-scale single cells. Additionally, we carried out process demonstration tests using pilot-scale fuel cell stacks. Our results indicate that the technology is feasible and effective.
State-of-the-Art Review of Lost Circulation Materials and Treatments — Part I: General Trends and Uses
Authors: Alkinani Husam H. , Al-Hameedi Abo Taleb , Dunn-Norman Shari , Al-Alwani Mustafa A. , Mutar Rusul A. , Al-Bazzaz Waleed H.
Published: November 2019

One of the major problems facing the oil and gas industry is the problem of lost circulation. Millions of dollars are spent every year to treat this problem. Lost circulation can be occurred due to high permeability, natural fractures, induced fractures, or caves and vugs. Many major oilfields in the world are susceptible to lost circulation while drilling troublesome formations. The aim of this work is to understand the current trends and uses of lost circulation treatments worldwide. This work will be the first part which only focuses on the trends and uses. The other part (Part 2) will be focusing on probability and cost analyses.

Lost circulation treatments data were collected from more than 2000 wells around the world. Various sources were utilized to gather data such as daily drilling reports, technical reports, petroleum literature, etc. The data were clustered based on the type of loss (e.g. partial, severe, and complete), the reason for lost circulation, and the location where the treatments applied. An interactive dashboard was created to better understand the trends and uses of the lost circulation treatments worldwide. The created dashboard is adaptive for the user's preference and can be utilized easily.

The results showed that the pill of LCM treatments was the highest treatments used to treat partial loss worldwide with a good probability of success. While the high concentration acid soluble LCM treatment showed the highest use among other treatment to treat severe loss with a good probability of success. Moreover, cement plug + high viscosity (HV) mud treatment had the highest uses to treat complete loss with an acceptable probability of success. In addition, cement plug was the leading treatment used to treat partial, severe, and complete loss with a good probability of success. Nonetheless, it is not a usual practice to use cement plug to combat partial loss since there are other cheaper alternative treatments. Finally, this work will give clear insights into the current trends and uses of lost circulation treatments worldwide.
A Comprehensive Scheme for Application of Low Salinity Waterflooding Technique in Mature Fields
Authors: Elmasry Hossam , Anwar Mohamed , Moussa Esraa
Published: November 2019

The main seek for the whole oil industry is to find a way to prolong the economic life of the existing mature fields, as a result of the difficulty of finding new big assets. The waterflooding efficiency can be dramatically enhanced by the application of new technologies with the target of sweeping higher amounts of unswept oil. IOR/EOR methods are investigated to improve the oil production from the giant Belayim Onshore mature field located in Gulf of Suez, Egypt. The field was previously developed by using sea water peripheral injection. The existing water injection strategy is found not be the optimum strategy to increase the sweep efficiency and the recovery factor as a result of the huge lateral heterogeneity and different mobility ratio.

This paper describes the work done to improve the efficiency of water injection by the application of different IOR/EOR technologies specifically Low Salinity water. First, Coreflooding experiments on porous medium have been performed in the tertiary mood to detect the effect of IOR compared to the sea water injection. It was found that LS can increase oil recovery nearly to 7% more. After finishing the lab phase, simulation runs have been performed to predict the enhancement on field scale. The coreflooding experiments have been simulated using a wettability alteration model to determine the LS parameters and the new relative permeability curves. These parameter were the input into a sector model of fine gridding. The model was history matched using the wells production and injection data for the LS pilot area under study. Different forecast scenarios have been run and the incremental increase in oil recovery was reported against the current water injection scheme

A number of Single Well Tracer Tests have been performed to detect the effect of Low Salinity water flooding on well scale. The test was designed to incorporate a number of injection, production and shut in cycles in the pilot well with the aim determining the residual oil saturation with the current scheme of sea water injection and after switching into low salinity water. It was found that Low salinity water has achieved very promising results that produced a remarkable reduction in Sor at the range of (5-11) saturation units.

In order to estimate the full-field effect of the LS waterflooding as a promising EOR method, all the major aspects have been taken into account including the expected reduction in residual oil saturation, permeability alteration as a result of possible fine migration or clay swell and the possible change in the sweeping efficiency.

Finally, all the produced results from the experimental and simulation work have been incorporated into an economic study to determine the feasibility of constructing a desalination plant for the full-field application phase
Utilization of Mud Logs for Oil Fraction Quantification in Transition Zones and Low Resistivity Reservoirs
Authors: Torlov Vladislav S. , Bonavides Clovis S. , Al-Qubaisi Khalid A. , Fernandes Alan K.
Published: November 2019

Accurate quantification of fluid fractions in transition zones and low resistivity pay reservoirs often poses a challenge to the interpreter. Dry oil production from low resistivity intervals, mixed flow production, or disparity between formation evaluation analyses and surface tests can lead to lower confidence in the downhole measurements or interpretation and increase the uncertainty of the calculated hydrocarbon volume in place. A variety of measurements may be exploited to mitigate these concerns and, in this paper, the authors present an assessment of the relationship between normalized hydrocarbon levels while drilling, and computed oil fraction from wireline logging of logging-while-drilling (LWD) measurements based on a comprehensive dataset of various surface and downhole measurements. The study investigated the validity of advanced mud logging data for oil fraction quantification for particular borehole and reservoir settings and found a consistent trend across the range of bulk oil proportions and normalized gas values. The results of the obtained regression, and alternative cluster-based models are presented. The sources of uncertainties and possible correction approaches are discussed. The findings suggest that in consistent environmental and reservoir settings, advanced mud logging data can be used for hydrocarbon fraction estimation while drilling to assist in pay zones delineation and identification of fluid contacts. Potential was also seen to identify intervals of fractional flow production in transition zone reservoirs, low permeability formations, and dry oil production in low resistivity pay cases. In addition, developing such relationships and models is useful for correct identification of mud log artifacts, such as produced hydrocarbons while drilling, gases from circulation, and zones of overpressure. Another application is to assist in defining petrophysical model parameters, aiding or replacing other supporting information.
Electrification of Offshore Oil & Gas Fields Using Offshore Power Distribution Hub: A Study of Submarine HVAC Power Cables Systems Solutions
Authors: Renaudin Fabien , Gaudissart Simon , Toulotte Maxime
Published: November 2019

Traditionally, offshore oil and gas installations have been electrified by means of power generation equipment installed on the platform themselves. In recent year however, more and more offshore assets have been electrified by transmitting them power generated onshore through high voltage submarine power cable.

The alternative solution studied in this paper is the use of an offshore electrical power distribution hub connected to onshore power generation with a high voltage submarine power cable and supplying power to other offshore assets.

The focus of this study is put on the high voltage submarine power cable system transferring a power of 300 MW from an onshore power plant to the offshore power distribution hub located in the Arabian Gulf region.

Cases considering different transmission length, ranging from 50 km to 100 km and different voltage levels, i.e. 220 kV, 275 kV and 380 kV, are defined, analysed and compared technically. An overview of the technology current state of the art is also presented.

In addition, an economical assessment including manufacturing, installation as well as cost of losses over a period of 30 years is performed for the various cases.

With the high focus on cost and increasing concern for environmental impact in the industry, alternative solutions for the electrification of offshore assets are necessary. This study aims to demonstrate that a offshore power distribution hub supplying offshore assets with power generated onshore is a technical and economic viable alternative.
Saturation Forecast Using Machine Learning: Enabling Smarter Decision-Making Capabilities
Authors: Saumya Sachit , Naqeeb Ibrahim , Vij Jitesh , Khambra Isha , Kumar Apoorva
Published: November 2019

In recent times, several machine learning algorithms have been utilized to analyze massive amount of data and provide fast and effective smart solution. To monitor the saturation over time, reservoir saturation tool is run in each well to provide the cased hole saturations. A single well may have as many has 15-20 runs over time which provides an estimate of present saturation, depletion across reservoirs or any other changes in saturation profile to EOR system in place and its impact. This paper demonstrates the idea of the use of machine learning algorithm to perform a time lapse saturation analysis and present a saturation forecast based on class-based machine learning combined with the time series modelling using multiple time lapse runs in a single well for a field. The first step involves using an unsupervised class-based machine learning model that classifies the input petrophysical data into set of classes with distinct similarity. The next step of the workflow involves using time series modeling on each of the obtained classes. Different methods were studied and eventually "Prophet" was used for time series modeling to forecast saturation over time. A way forward and game changer is propagating the classes to multiple wells with multi runs and predict the changes in saturation and pressure for a formation across a field to make holistic interpretation. Reversing the time series modeling can also provide an estimate of OH conditions and original hydrocarbon in place. The use of CBML and time series modelling for petrophysical saturation evaluation will open new doors to understanding of fields already under production and introduce smart decision-making capabilities. The idea presented in this paper can be implemented in different fields across the globe with different formation settings and EOR system in place and can be further advanced in terms of providing deep insight and interpretation like forecasting the change in reservoir pressure.
Hydraulic Fracturing: Best Remedy for Condensate Banking Effects in Tight Gas-Condensate Reservoirs
Authors: Al Habsi Ghaleb , Ghanbarzadeh Soheil , Motealleh Siyavash , Al Busafi Badar
Published: November 2019

Available headroom (difference between dewpoint and reservoir pressure) in liquid rich gas reservoirs and drawdown scenario affect the condensate dropout near the wellbore. Although effects of the liquid dropout are well understood in radial system, addition of hydraulic fracture in the low perm reservoirs complicates the saturation profile in reservoirs. Massive hydraulic fracturing in vertical tight sand wells adds effective surface area to flow and can mathematically be considered as placing long horizontal wells to reduce overall well draw downs. This work shows that this additional contact with matrix rock, therefore, can play a major impact in mitigating or postponing the impact of skin caused by condensate banking.

This paper presents a real case of Pressure Transient Analysis (PTA) for hydraulically fractured wells in unconventional gas-condensate reservoirs. Detailed analysis of PTA will be discussed and addressed using analytical and high-resolution numerical models in which compositional multi-phase flow is considered. The numerical model is history matched and fine-tuned on pre-frac and post-frac well test results. The impact of hydraulic fracture half-length, fracture conductivity and matrix relative permeability on condensate banking effects will be addressed via a numerical simulation study for various scenarios.

The paper will demonstrate the value of hydraulic fracturing in reducing condensate baking effect on well productivity and, by inference, the impact on the long-term economic value of gas-condensate wells.
Lean Thinking and Gap to Potential: Achieving Breakthrough Well Delivery Performance
Authors: Al Busaidi Faisal , Al Hinai Faisal
Published: November 2019

This paper discusses how Lean thinking approach has been used to develop a new way of measuring the drilling performance, called "Gap to Potential (GtP)". It describes the methodology of developing Gap to Potential and highlights the implication of using it in one of the fields in Sultanate of Oman.

One of the foundational components of Lean is to make performance visible to the team and organization. Hence, The GtP concept was initiated in 2017 as a new process performance measurement concept aimed at motivating and developing teams to problem-solve their way towards aspirational goals. The GtP measures the gap between the average time it takes to drill a particular well type in a certain field with the Best Composite-well Time (BCT) ever achieved. The aspirational goal is to beat the BCT; when the previous BCT is met, the GtP concept generates a new BCT to continually generate a problem-solving and improvement culture. The GtP measurement was digitalized and visualized using an advanced analytic tool. Making the GtP visible to key stakeholder at all levels creates a sense of ownership and pride within the organization.

In 2017, Well Engineering team achieved lowest cost per well for the last 10 years with a further 4% improvement on 2016 performance and 7% reduction in well cost compared to the Well Cost Catalogue of 2019. GtP has now become part of a common performance dialogue at all levels in the Well Engineering organization. Despite of being relatively simple it its development, it has proven to be a powerful catalyst for boosting team development, building problem-solving capabilities and visualizing success. Once teams become familiar with the GtP approach, performance analysis and improvement become part of a daily routine. The success of the GtP for drilling has now created further replication across the organization, such as GtP for well intervention and energy management GtP.

The concept of visualizing GtP creates a sense of ownership at all levels driving behaviors of increased engagement and collaboration between drilling teams and assets as well as other supporting teams. Better uptake of other Lean ways of working that help structure the work and drive performance such as Leaders Standard Work (LSW) and Standard Operation Procedures (SOP). This concept is now being replicated for well services operations and can be applied to any type of activity, either technical or non-technical.
Bridging the Natural Gas Gap: An Integrated Approach to De-Risking the Development of LNG-to-Power Infrastructure
Authors: Fangmeier Clark
Published: November 2019

This paper focuses on overcoming the challenges of developing integrated gas-to-power infrastructure. It discusses strategies for driving the viability of LNG-to-power megaprojects– providing considerations for financing and risk mitigation. Additionally, it examines the merits of adopting an integrated approach to project development, with a close look at the Gas Natural Acu (GNA-1) project in Rio de Janeiro, Brazil, which is the largest LNG-to-power development in Latin America. For the project, the power plant's original equipment manufacturer (OEM) became a 33% equity investor. This, along with commitments from other strategic equity investors, significantly de-risked GNA-1 and played an important role in reaching final investment decision (FID).

The paper offers detailed insight into the inherent risks and challenges LNG-to-power project stakeholders encounter during development. It also discusses how these risks can be addressed and how projects can be made more attractive to institutional investors through innovative project financing structures. The ability to secure financing from a variety of equity sources with strategic interests in the project is critical, as it allows the sponsors to raise a greater amount of debt than would otherwise be possible. In doing so, sponsors are able to assume limited recourse after project start-up and in many cases, enjoy customized loan repayment profiles, which contributes to better overall project economics. Co-financing also reduces investment risk and allows for capital to be raised at a relatively low cost, which benefits all stakeholders.
A Novel Approach Towards Cementing Design Achieved Significant Improvement in Long Term Zonal Isolation
Authors: Suleiman Ala , Hilal Bashar , Paila Phalgun , Abdelhadi Sahir , Alwahedi Khalid , Alkindi Rashid , Al Marzooqi Abdulmohsen , Khalifa Mahmoud , El Atrache Bassam , Singh Rudra , Ghulam Hammad
Published: November 2019

Well integrity is becoming more challenging with drilling of deeper, highly deviated and horizontal wells worldwide while the current market scenario is driving every stakeholder to execute their scope of work under ever revising AFEs. The scope of this paper is to present an optimized approach to improve quality of cement jobs while having a good long term zonal isolation across all the targeted formations and further eliminating the additional costs required for remedial jobs.

There are various challenges that need to be dealt with when cementing complex wells such as uneven cement distribution around the casing due to insufficient mud removal, inadequate hole cleaning and poor casing standoff. All these challenges were addressed by in-house developed optimization methodology. The elements of this methodology that positively influenced the quality of the cement bond were (i) Optimizing the rheological hierarchy between the cement, mud and spacer design to create optimum flow during the cement job (ii) Improving hole cleaning efficiency by applying tailor-made spacer technology with aid of modeling software (iii) Optimizing the centralizer profile by including non-survey stations.

The in-house developed optimized methodology has yielded excellent results with significant improvement in the cement bond logs when compared to the offset wells. This paper will present the methodology adopted in detail along with the field example of a well in an offshore island that has measured success against the key improved elements.

The rheology of the fluids was adjusted to improve the fluid displacement in the analytical software which has played a big role in improving the hole cleaning efficiency. In addition, application of tailored Spacer design has not only showed improved mud removal effectiveness but also helped with reducing the channeling alongside the best optimized centralization found in the field in terms of type, quantity and placement across various formations and direction profiles along the well bore.

This paper will also compare different logs in the same field to show the improvement against the new methodology and practices adopted that helped in achieving complete zonal isolation across all formations. The new optimization methodology has resulted in significant improvement in outcome of cement logs across production casing in offshore island indicating an excellent zonal isolation and adherence to well integrity requirements. The key elements that were improved are now being adopted across all the jobs in the field and nearby fields.
Integrated Downhole Multiphase Flowmeter and Autonomous Inflow Control Valve
Authors: Bjerke Anita , Aakre Haavard , Mathiesen Vidar
Published: November 2019

The Smart Autonomous Inflow Control Valve (S-AICV) technology is presented. This smart well sensor will prevent water and gas breakthrough and at the same time operate as a multiphase flow meter. The single compact system can be used in both mature and new field to map fluid flows along the well in oil reservoirs and at the same time autonomously controlling the production of unwanted fluid in the individual zones. This will provide the oil companies with detailed reservoir conditions data to have a better understanding of well production and drainage, and hence optimize future AICV well installations.

A multiphase flow model is developed which correlate the three pressures located inside the S-AICV (P1, P2 and P3) to flow rates of gas, water and oil going through the valve. At breakthrough of gas and/or water the S-AICV will detect pressure changes when the fluid composition changes. This model utilizes this pressure changes to distinguish between the different fluids and determine the flow rate and composition of inflowing fluid. The S-AICV application is designed for each specific field to achieve the desired functionality, and the user input parameters for this model need to be determined and individually adjusted accordingly to the fluid properties and the configuration of the valve.

This smart well sensor will extract data from the well and transfer the data to the surface via an optical fiber. The multiphase flow model will convert the signals to flow rates and composition, without compromising the autonomous and reliable AICV to meet the oil industry needs.

Existing measurement systems as tracers or various production logging tool are costly and complex. Separate multiphase flow meters can be installed in addition to the AICVs, but this is an expensive solution where only a fraction of the data can be gathered. The benefits of the S-AICV system are its ability to prevent water and gas production and at the same time continuously measure the flow rate and composition to register breakthrough within a low-cost package with maximizing data gathering.
An Integrated Approach to Tackling the Challenges of Drilling in a Highly Depleted Gas Reservoir
Authors: Zhang ZhongPeng , Wu Yan , Luo Lei , Wang Xueqin , Fan Yonghong , Yi Gang , Chen Chong , Zhao Fashou , Zhang Xiaoping , Liu Wei , Dong Hongwei
Published: November 2019

In many matured fields around the world, the infill well development faces multiple challenges; reservoir depletion caused by existing wells is unavoidable, the remaining area to be targeted by infill is typically relatively marginal, with thinner formations that still bear significant subsurface uncertainty compared with sweet spot area developed in the initial phase. In addition, some fields are impacted by PSC conditions, with a strict time constraint.

When developing infill wells several key aspects have to be considered: starting from potential severe mud losses, drill pipe stuck during the drilling phase, to formation damage, production interference with neighboring wells, earlier load up for gas wells etc.

Shell China developed an integrated approach by considering all these challenges, and successfully implemented it for the Changbei tight gas infill well project.

During the Design Phase, a series of core lab tests were carried out to evaluate the formation damage and related permeability reduction. The lab test results indicated that the permeability reduction as result of water encroaching into water wet rock formation is significant (+90%), causing a "water locking" effect. Another topic pertaining to the Desing phase in the Changbei field is the optimisation of the dual lateral well trajectory based on the expected depletion state of the reservoir. Also discussed is the horizontal well tubing size optimization, which accounted for the selection matrix based on KH, online date (related to PSC end) and expected reservoir pressure (depleted).

In the Delivery phase, the surfactant additive identified through the lab testing has been used into the drilling mud and completion fluid to appropriately mitigate the water locking effect. The lab test results demonstrated that a permeability improvement of at least 10% could be achieved. Furthermore, the surfactant concentration was optimized to maximise the emulsion effect for water treatment and the foaming effect during the drilling phase. This paper also covers the well flowback efficiency improvement achieved by additional nitrogen lifting and prolonged firing time.

During the Well Reservoir and Facility Management phase (WRFM), a study of infill well production interference with existing wells was carried out and the recovery could be maximized at the cluster level.
The Impact of PV Shades in Reducing Heat Stress in the ONG Drilling Industry in the Western Region of the United Arab Emirates
Authors: Siddique Abdul Hasib , Rodrigues Clarence , Simmons Rodney
Published: November 2019

Excessive heat in an oil/natural gas (ONG) drilling environment can have negative effects on workers, production levels and work efficiency. The United Arab Emirates (UAE) borders the Gulf of Oman and the Persian Gulf, and sits between Oman and Saudi Arabia. The summer temperature in the UAE can go as high as 51°C, which is extremely high for continuous outside work, especially considering that a 12-hour work shift is normal on the rigs. Due to global warming, average ambient temperatures in the summer are now generally higher than what have been experienced in the past. Although the differences are of only a few degrees, these small differences can make a big change in the work environment. Hence, companies have been trying to come up with engineering and administrative controls to reduce the effect of summer heat in this region. Photovoltaic (PV) array shades have been proposed in this paper to improve conditions for the worker. The Thermal Work Limit (TWL) has been evaluated in this study to understand the ability of PV shades in reducing thermal load on the body. TWLs have also been calculated without the shade and then compared against semi-indoor condition available on the rig. A model of PV shades has been designed to reduce the effect of heat stress keeping in mind the complexity of a rig move and other rig activities. Benefits of rooftop PV systems for area cooling are validated through previous studies and modeling. Heat flux modeling shows that solar panels can lower a roof's underside temperature by ~3°C. The PV array can also help in reducing heat loss during the cold winter nights. This paper also discusses the how this reduction of daily variability in surface temperatures under the PV shade helps to reduce worker's thermal stress.
Prevention of Well Control Incidents and Well Life Extension in Mature Fields
Authors: Yugay Andrey , Vorozhikhin Sergey , Daghmouni Hamdi , Al Shamsi Marwan , Yousef Abbas Ahmed , Abdelaziz Ahmed Saber
Published: November 2019

Well Integrity issues associated with barrier degradation due to corrosion could significantly impact on production results in mature fields. Sometimes those issues may lead to the severe well control incidents during production phase affecting on the performance of the facilities nearby. This paper describes the negative trend of well control incidents, which was changed, by using innovative approach of secondary barrier evaluation for wells with compromised primary barrier envelope. The objective is to share with the audience special practice of well integrity management using multiple barrier evaluation technology to prevent loss of pressure containment (LOPC) incidents. In addition, the method allows to extend the production life of wells with sustained annulus pressure (SAP) and continue operating those wells under specific conditions and periodic monitoring instead of immediate killing and securing. This "grace period" could be granted based on the known conditions of the secondary barrier envelope until the rig become available to fix the integrity issue and restore the well barriers.

Company started drilling activity in 1960's and since that time more than 4,000 wells have been drilled. All wells have carbon steel casings which serves as secondary barrier envelope in case primary barrier fail. Carbon steel easily gets corroded with time in case of insufficient protection and isolation from corrosive environment. Failure of both well barrier envelopes results in well control incidents. Uncontrolled release of hydrocarbons and other reservoir media to surface or aquifers has a strong negative HSE impact: it could be a reason for human injuries and deaths due to pressure, fire and H2S release, environment pollution, deferred production. Additionally, it is associated with unplanned increase in CAPEX and OPEX, reduction of business targets and KPI's, may cause negative impact on Company image and reputation.

Innovative proactive method of secondary well barrier evaluation, successfully used to prevent well control incidents, allows Operators to find the right balance between safety and operation, and extend the production life of the wells with integrity issues without jeopardizing safety and integrity conditions in the fields. Paper illustrates how 9 well control incidents have been prevented and 14 wells with compromised primary barrier envelope were allowed to operate for a limited period of time, until the integrity issues have been fixed.
Performance Enhancements through Mere Compliance with Air Filtration Standards
Authors: Rabia Hagar
Published: November 2019

This paper summarizes fuel gas consumption savings and enhanced efficiency benefits for operating Power Generation Gas Turbines. The cost savings and improved efficiency were achieved through the mere compliance with the latest air filtration standards.

European Standard for general ventilation air filters EN779 specifies fine filter class (F7 to F9) for filter element capturing particle sizes between 0.4-1.0 µm. Revised in 2012, a new requirement for Minimum Efficiency (ME) parameter was introduced for fine air filer classes. The new F9 filter elements replaced existing primary filters installed in a Power Generation Gas Turbine located in an ADNOC Gas Processing Site. Additionally, European Standard for high efficiency ventilation filters EN1822 revised in 2009 specifies filter element capturing particles at Most Penetrating Particle Sizes (MPPS). Efficiecy Particulate Air (EPA) - E12 filter class replaced existing high efficiency F9 filters. The upgrade also included replacement of D-Fog panels and primary filters' support mechanism with a new design.

To assess the potential benefits, a performance comparison study was carried out between two Gas Turbines. One Gas Turbine was upgraded with new air intake filters design; while the second was replaced with a new set of old filter elements. The new support mechanism for the primary filters eliminates dust bypass and filter looseness. The upgrade of existing D-Fog panels extends the life and maintainability. The new elements featuring Polypropylene fibres constructed in a 3D mesh can be washed and reused up to two times before replacement. Both Gas Turbines were started and operated for the same time interval. The study's results showed an increase in efficiency in terms of compressor isentropic efficiency and compressor polytropic efficiency at 2.14% and 1.61% respectively. An overall Gas Turbine efficiency increase of 0.35% was also realized. The fuel cost for 1MW generated was reduced by 0.39 USD/MWhr.

This tested and proven practical study is a testament to Gas Turbine users from all energy sectors across the globe. The verified financial gain and efficiency enhancements are great incentives for other Gas Turbine users to comply with the latest air filtration standards.
Predicting Mean Time to Failure in Horizontal Wells through Metal Loss Analysis and Produced Water Composition
Authors: Ofori Bruce Agyapong , Wei Mingzhen , Bai Baojun , Al-Kamil Ethar Hisham
Published: November 2019

Loss of well integrity in many horizontal wells in the United States has resulted in huge capital losses to several operating companies. The occurrence of corrosion in horizontal wells in the US is attributed to several reasons. The deposition of iron (Fe) and manganese (Mn) from manufactured steel pipe and the inability to effectively treat the laterals plays a major role in corrosion mitigation in horizontal wells. Corrosion inhibitors are injected into the wells to help reduce the corrosion rates, however the effectiveness of these injection applications is hampered by the types of well design and fluid dynamics. Loss of Fe/Mn in the lateral sections of the well is a major concern for the oil industry. This research will investigate the amounts of Fe/Mn contributions from the laterals and also investigate the relationship between iron and manganese counts from produced water from oil fields in the US. This research will further investigate the mean time to failure in the laterals and suggest proactive plans for mitigating failures based on findings.

High Fe/Mn concentrations could lead to corrosion in producing wells. High densities of Fe/Mn found in produced water analysis reports has been attributed to the abundance of these two elements used in manufactured steel pipe. These elements are used due to their abundance in manufactured steel pipe and their lack of natural presence in formation fluids. Fe and Mn have a known ratio in steel pipe of approximately 100:1 (depending on steel type). These high concentrations could ultimately compromise the wells integrity.

This research emphasizes the need for considering iron and manganese counts as integral part of the corrosion monitoring. Moreover, considering the long lateral casings, which spans several thousands of feet in the US, injection of corrosion inhibitors will be ineffective in reducing Fe and Mn loss in the lateral sections. Monitoring of Fe and Mn over such long laterals is challenging and costly. It has therefore become crucial for oil companies to thoroughly understand the Fe/Mn contribution from the laterals that could lead to corrosion and develop mitigation strategies to lower corrosion rates in such high-risk wells. This will help to implement remedial measures to better define corrosion rates and quantify the risk of failure. This will also enable oil companies allocate resources for further development and not several remediation efforts.
Condition Based Maintenance for Oil and Gas Industry Based on Data Reconciliation Techniques
Authors: Craciun Ionel , Lecoq Frederic , Digavalli Suryaprakash
Published: November 2019

This article proposes a new approach for dealing with maintenance issues for large industrial processes. The case study is taken from an industrial implementation of a condition-based maintenance project for the heat exchangers from the crude preheating train of a European refinery. The application was developed based reconciled data using the advanced data validation and reconciliation tool, VALI, developed by Belsim.

The article proposes the riguroous calculation and monitoring of the fouling factors of heat exchangers as crucial parameter to alert the operator about the condition of the heat exchangers. The calculation of fouling factors is performed automatically by the application with a minimum initial input effort from the part of the modeler: design date for film transfer coefficients for the both sides of the heat exchanger. Industrial data shows that the heat exchangers from the crude preheating train are prone to relatively quick fouling. The financial analysis of the impact of the fouling problem on the normalized daily fuel consumption in the crude furnace has shown that the high initial financial gain of a preheater cleaning can amount to as much as 20% of daily fuel cost. However, the performance degradation sets in very fast and the high initial gains are not sustained for prolonged periods of time. On the other hand, the overall performance degradation slows down in time and the performance of the crude preheating train stabilizes at lower values, making the decision process for heat exchanger cleaning more difficult in situations of pressures to maintain production volumes.
Identify and Recommend High-Value Improvement Opportunities in a Geologically Challenging Reservoir
Authors: Al Dhanhani Helal , Fazal Ayub , Selvam Balakrishnan , Obeta Chukwudi , Herrmann Rolf , Kosik Ivan John
Published: November 2019

This abstract proposes an optimum plan for offshore Abu Dhabi carbonate reservoir capitalizing on all historic and ongoing lessons learned and defining clear actions, pilots and completion technologies to achieve and sustain desired production target. Different completion designs will be discussed in this paper to define the optimum completion strategy per well and area.

The completion designs were as follows: Single completion with 10000ft (10k') lateral lengthTri lateral with 10k’ branch (total 30k')Fishbone with 6×6k’ branches (total 18k')

Long standing strategy to develop this reservoir with line drive depletion. The base plan is to drill a single lateral with 10k’ lateral length and 1 km spacing with a plan to convert the base producer to an injector while the line drive spacing is downsized to 500m. The total footage of reservoir contact in this case is 10K’ in base case followed by 20K’ in the infill timing. The other completion designs are suggested to increase the reservoir contact at initial times to reduce the pressure drawdown in the production wells. Fishbone consists of a cemented motherhole with 6 branches 3K’ laterals at 30° angle (total footage ~18K'). Another completion design is the tri-lateral which consists of three branches parrelel to each other with reservoir contact ~30K'. The conversion strategy is not possible by the application of multilateral production wells due to the wellbore collision concern with infill drilling adjacent to multilateral wells. Note that branches in the fishbone and tri-lateral well designs are left as open hole due to liner access concern. For production performance comparison, due to well management logic of the model it was necessary to normalize the individual well profiles to attain an equivalent online date and equivalent amount of production days. The objective of normalization was to provide a fair and unbiased comparison of the competing completion types.

Calculation of the net present value (NPV) and comparing it for each well while taking into consideration the cumulative oil recovery results in a hybrid development scenario with preferred multilateral and preferred Monobore development wells. The dynamic model results were used to compare well by well the cum recovery and the NPV, which led to create an economical development scenario without jeopardizing the ultimate recovery.
A Distinctive Approach to Performance Measurement of a Digital Transformation Programme in an Energy Company
Authors: Talamonti Marco , Siciliano Lorenzo
Published: November 2019

The digital transformation in the energy sector has specific features arising from the characteristics of the sector, the dimensions of the assets and the complexity of the technologies and processes utilized in the research, production, transformation, and transportation and sale of energy to the end-user.

This paper describes the performance model developed in Eni to measure the success of the digital transformation programme. A top-down approach was developed for the three main sectors/areas impacted by the transformation i.e. the Industrial and Commercial sectors and the Support Functions area.

The model is structured in 3 layers: Strategic Goals, Company Results and Business Lines / Assets Operational Performances. For each layer, different sets of KPIs have been identified to measure the contribution provided to the Company's targets both operational and economic, from the digital transformation programme. Those KPIs are also complemented with indicators to monitor the progress of the on-going initiatives/projects and of the Change Management programme. Some preliminary results and next steps are also discussed.
Characteristics of IX1 Digital Acquisition System
Authors: Li Zhengzheng , Yan Wei , Huang Lei , Xia Ying , Yang Maojun
Published: November 2019

Oil companies has spent decades in pursuit of obtaining high quality seismic data at lower cost. Until recent years, with the development of the geophysical theories, oil companies have shifted focus to low frequency seismic data while keeping the advantages of large number channel operations. The conventional geophones, due to the restriction of working principles, don't have good low frequency response. And, it usually costs more for geophysical companies to purchase large number instruments. The iX1 digital acquisition system is designated to offer fundamental improvement for seismic prospecting, acquiring high-resolution seismic data at economic prices. This article describes the characteristics of iX1 digital system, ground equipment and digital sensor AccuSeis SL11.