bluuebunny/crossref_metadata_2025 huggingface dataset:
Debottlenecking of FPSO Facilities by Compact Separators
Authors: Krebs Thomas , Balk Wouter , Verbeek Paul , Akdim Reda , Kruijtzer Govert , Ibohouten Boubker , Ogazi Isaac , Okoh Godwin , Arntzen Richard , Shell AS Norske , Paranjape Mrudula
Published: November 2016

The Bonga FPSO was designed to process 280 MBLPD gross liquid, constrained by the three-phase low pressure (LP) separator capacity. The projected production forecast indicated that additional future volumes of produced fluids from the Bonga field could exceed the design capacity of the installation. FMC's Inline PhaseSplitter was identified as a solution for debottlenecking the three-phase LP separator liquid handling capacity. The PhaseSplitter is a compact pipe-based cyclonic separator that splits the feed flow into a gas stream with limited liquid carry-over and a liquid stream with limited gas carry-under. The performance objective for the PhaseSplitter is 70 % or more gas removal while keeping liquid carry-over in the gas outlet below 1 % volume fraction.

In this paper, we report results of a technical qualification program (TQP) for the PhaseSplitter as a debottlenecking tool for the three-phase LP separator. We used a down-scaled 3 inch pipe of the PhaseSplitter as compared to a 24 inch full-scale field unit. A model fluid whose physical properties resemble the Bonga fluids was used, thereby giving credence to the test results. A test matrix covering a range of representative feed conditions was probed: gas volume fraction (GVF) 75 - 90%, water cuts 20 - 80% and inlet momentums 4500 - 11000 Pa. We measured the percentage of gas removed from the feed and the amount of liquid carry-over into the removed gas as function of the flow split to the gas outlet.

The results show that for almost all test conditions, acceptance criteria that were set for the PhaseSplitter were met, i.e. 75 - 80% gas removal and liquid carry-over with the gas less than 1%. Gas-liquid separation performance gradually decreases with decreasing momentum and GVF in the feed. We observed no dependence of separation performance on the feed water cut. We plotted the results as function of the normalized flow split showing universal trends. These trends provide a means to control the separation performance by monitoring the pressure drop over both outlets. We conclude that the PhaseSplitter delivers a robust performance under steady-state conditions over a wide range of operating conditions.
Enhanced Multilateral Reservoir Monitoring for the First Time in Offshore Abu Dhabi Utilising New Well Intervention Technology
Authors: Bilbeisi J. , AL Mehairi O. , El Sayed M. , Al Mansoori A. , Berrim A. , Keshta O. , AbdelFattah Y. , Sudhakaran S. , Chehabi W. , Smith A.
Published: November 2016

Changing oil field development economics has pushed the trend towards developing multilateral wells to increase production and maximize oil recovery utilizing advanced well configurations. However, to focus on maximizing the value of multilateral wells by addressing reservoir and production challenges; efficient reservoir management has remained a challenge. Accessing multilaterals has not been possible with conventional Coiled Tubing logging techniques. Current available technologies for deploying Production Logging services in the multilaterals are of less success, due to hardware limitations.

The challenge was to access slim hole laterals from the mother bore in order to perform reservoir surveillance activities namely production logging as well as acidizing operations in laterals previously inaccessible. The information gathered from this intervention would improve the overall understanding of the reservoir and well behavior thus enabling the operator to manage the multi-lateral wells’ individual drains, ensure production assurance and sustainability and revisit the development plan for the tight reservoirs based on proper reservoir evaluation.

With the introduction of a new lateral intervention tool, the operator was able to successfully access a lower drain drilled from a window in the casing with efficiency and certainty. The smaller size tool used on this operation had an OD of 2 1/8", which is ideal for accessing laterals in wells with slim hole completion.

The tool helped in accessing the lateral and provided the operator the opportunity to perform production logging operations. This had previously not been possible with conventional technology which was attempted numerous times without success.

The need for mobilizing a rig was prevented in addition to the reduced foot print of the required equipment and personnel required reflect substantial reductions in time and cost for this intervention.

This paper introduces the knowledge learned from the world’s first multi-lateral accessibility and production logging operation in the UAE by applying a new multi-lateral accessibility on Electric Coil Tubing through detecting the multilateral window and activating a powered arm for entry into the lateral section.
Impacts of Dense Phase Flow on Pipeline Capacity - Case Study
Authors: AlRaeesi Fatima , Al Kaabi Nouf
Published: November 2016

In view of ADNOC's vision towards optimization, efficiency and profitability, GASCO along with its Operating Companies is committed to ensure process design optimization. In line with this a project was implemented using the same existing pipeline to accommodate the additional feed gas coming from offshore production facilities.

A 30-inch dense phase pipeline is originally designed to accommodate a normal capacity of 200 MMSCFD Feed Gas with an operating pressure of 148-97 barg (varies based on transported gas composition). The design capacity of this pipeline is 530 MMSCFD. The feed gas supplements the LP gas already being delivered through the OAG facilities and this brings the total of LP OAG and HP Integrated Gas Development (IGD) gases to 1000 MMSCFD.

Several studies were conducted such as dense phase pipeline transient hydraulic analysis to ensure the pipeline's ability to handle the additional capacity running at 207km long.

Additional capacity can be handled in the existing 30-inch pipeline in terms of operational modification within the operating envelope; for example, the inlet pressure to the pipeline is limited to a maximum of 152 bara. The analysis for this study proved that the combined OAG and IGD feed gas does not cause the pipeline to experience temperatures close to the minimum design temperature of -10°C. The limited design capacity was overcome by increasing the operating pressure in order to achieve the dense phase region and the new capacity.

A fluid within the dense phase region has significant benefits, primarily emphasizing on a low CAPEX and OPEX, amongst which are the following: Lower fluid velocitySmaller inside diameterHigher potential for NGL extractionSlug Catcher is not required
First Time Offshore Abu Dhabi-Successful Appraisal Drill Stem Testing Operations in Extreme Sour Environment - A Case Study
Authors: Iabbassen N. , Al-marzouqi A.M. , Slatewala H.S. , Jimenez J. , Karim H. Abdul , Sax K. , Shateri A. Al , Sutherland R. , Barrow D. , Ameri F. Al , Huda S.
Published: November 2016

As part of of the studies being done aiming to secure bigger gas and oil resources in the UAE, several fields have been undergoing extensive appraisal & evaluation efforts over the past few years. Starting from a review of seismic, petrophysical and well test data from discovery wells, new appraisal wells have been drilled, logged and tested to refine reservoir models and evaluate static and dynamic reservoir properties.

With a focus on determining economic viability, productivity and reserves, well testing is a key source of information, yielding fluid samples, productivity, formation mobility and prodiving key indications about optimal completion options such as well inclination or completion method.

To demonstrate the existence of moveable petroleum in a reservoir and/or to provide an indication of the potential productivity of that reservoir, well testing is of particular importance to obtain critical information about undeveloped reservoirs. Well testing provides a full understanding of the attributes of a well so that it can be operated profitably and efficiently.

A recently drilled appraisal well includes deep oil / gas reservoirs containing up to 38% of hydrogen Sulfide (H2S) and 7% of carbon dioxide (CO2) was successfully tested using Drill Stem Test (DST) in Abu Dhabi offshore field.

In order to successfully appraise this field with its specific nature of reservoir fluids that makes all drilling and data gathering operations extremely challenging, many problems had to be solved in well testing techniques. It had to focus on optimal fluids containment and minimization of release. To achieve those aims, several modifications of the equipment were required.

It required extensive risk assement sessions with all service providers and rig contractor, in addition to the real time monitoring of all surface and downhole parametres. A systematic multi discipline planning approach with attention to detail, rigorous planning and team work, were some of the key success factors in delivering the objectives in a safe and efficient manner.
Design and Analysis of Leg Jetting System for Offshore Jack-ups Rigs
Authors: Roy Mintu , Fandy Hesham
Published: November 2016

Jack-ups used for offshore wind turbine installation pose numerous challenges during extraction. The seafloor terrain differs from location to location and the entire design and installation needs to be planned according to the specific requirements of each project. This research was specifically focused on the challenges faced in extracting the spudcan and proposes a jetting system design that can assist in smooth extraction. The research tackled practical challenges that affect the performance and safety of leg jetting systems, a practical leg jetting system design is suggested suitable for wind turbine installation vessels. The design was simulated where different case scenarios at different water depths and spudcan penetration levels were checked for its safety and operation.
Safely Landing the First Oil Producer in the Barents Sea
Authors: Tosi Gianbattista , Stensland Dag , Winterton David , Zappalorto Luigi , Wang Haifeng , Dupuis Christophe , Denichou Jean-Michel , Horstmann Mathias
Published: November 2016

Goliat was the first oil discovery in the Barents Sea and holds 174 million barrels of recoverable oil. It is operated by Eni Norge (65% share, with Statoil holding the rest of the equity). Finding oil is important, but safely and efficiently developing it is critical. The remoteness of these frontier projects amplifies the consequences of any delays or issues. Risk prevention and mitigation is the object of particular attention in this new frontier area. Landing the first producer was a particularly sensitive operation, requiring a safe stop a few meters above the top of the reservoir to reduce the risk of landing the section within the reservoir gas cap bearing sandstone.

A geometrical landing would be limited by a depth uncertainty of more than 10 m true vertical depth (TVD): relying on surface seismic information is subject to seismic time-to-depth conversion and the inherent limited resolution of seismic data. Taking these uncertainties into account normally requires setting the casing long in advance of the reservoir top, giving way to a much longer portion of the reservoir section exposed to the overburden shales, with consequent 8 ½’’well bore instability issues and risk of plugging the completion screens.

For the Goliat well, the operator adopted a different approach to land the objective while preventing the risks of setting casing too soon or too late. A new ambitious objective was set: stopping and casing as close as possible to the reservoir, but no closer than 5 m TVD. This could only be done by using the latest generation of deep directional resistivity (DDR) logging-while-drilling tools in the 12 ¼" section, increasing both the precision and the accuracy of the landing by relying on a direct detection of the reservoir top before drilling into it.

The DDR real-time automatic inversion of the subsurface layering revealed the top of the reservoir from 19 m TVD below the bottom hole assembly, a new record. By tracking the top boundary, even at a steep inclination near 70°, the operator confidently stopped drilling when the bit was 6 m TVD above the top of the reservoir, as planned, safely minimizing the distance to be drilled in shales before intersecting the reservoir. The distance to the reservoir was verified in the next section drilled.

The use of DDR for landing wells accurately either above or just below a top reservoir is now a proven powerful option for drilling programs in which risk prevention is required at the top of the reservoir.
Oilfield Build Own Operate BOO Projects - A Good Execution Strategy for the Current Low Oil Price Environment
Authors: Bernstein D. , Gonzalez C. , Heikal M.
Published: November 2016

Objectives/Scope

In the current low oil price environment, oilfield Build Own Operate (BOO) and Build Own Operate Transfer (BOOT) projects deserve consideration. Although generally the objective of BOO and BOOT projects are to reduce upfront capital costs and transfer risk to the BOO contractor, BOO and BOOT projects also offer excellent opportunities to incentivize innovation and reduce project lead time to complete, lowering project life-cycle costs and accelerating project returns. If the BOO project is structured properly - safety, quality, and reliability are not sacrificed.

Methods, Procedures, Process

This paper compares and contrasts BOO and EPC projects to describe advantages and tradeoffs for successful application of BOO projects. The performance of the Kuwait Oil Company (KOC) EPF-120 project in North Kuwait is reviewed, as a successful example of the application of BOO projects in the oilfield. The EPF-120 project is a BOO grass roots centralized Early Production Facility that processes 120,000 BPD of crude oil, 84,000 MMSCFD of gas and 80,000 BPD of produced water. The project has now been in service for the full term of its five years operations contract.

Results, Observations, Conclusions

The typical structure of BOO projects and EPC projects are described, and conventional EPC projects are compared to BOO projects. Incentives and disincentives for innovation are discussed. Typical project timeline for EPC projects will be compared to BOO project timelines. Mechanisms to achieve quality, safety, and reliability are provided. As an example of the opportunities that BOO projects offers, operations, maintenance, environmental, and safety performance of the EPF 120 project is reviewed, and examples of innovation implemented for the EPF 120 and for other BOO projects are provided.

Additional costs of BOO projects - namely risk and financing are provided and compared to potential reduced life cycle cost and reduced project completion timeline. Operating challenges to execute a BOO project in an existing oilfield are presented. Trade-off between flexibility/innovation and specification/standardization are also discussed.

Novel/Additive Information

BOO is a solution in the oilfield to provide innovation and improved schedule without sacrificing quality, safety, and reliability. The skills required to successfully execute a BOO project will be detailed and include the following: process engineering and Front End Engineering Development (FEED) skills, capital and operating cost estimating capability, Engineering, Procurement, and Construction Management (EPCM)
A to Z of Gas Tracers - A Decade of Learning and Experience
Authors: Khan M. N. , Iwama H. , AL-Neaimi A. , AL-Shehhi O. , Chatterjee M.
Published: November 2016

In interwell tracer studies, reservoir complexities often make tracer breakthrough time difficult to assess. Although reservoir simulation studies serve as an effective tool in predicting a breakthrough, the tracer behavior in the real porous media sometimes present fascinating surprises. The proposed paper discusses a crestal gas injection project that was carried out in a super-giant heterogeneous carbonate oil field operated by ADMA-OPCO.

The field has been on production since 1960s with peripheral water and crestal gas injection as the current means of maintaining the reservoir energy. In 2006 a crestal gas injection project was initiated to support the production from the wells lying away from periphery. Alongside, a tracer study was initiated to track the injected gas movement and hence to find out the effective distribution pattern of the injected gas.

The tracer deployment was intentionally delayed by two years to equalize the crestal pressure distribution and to observe the natural injection gas diffusion pattern. The simulation results predicted a prolonged breakthrough period for the injected tracers, and therefore, the sampling scheme was designed accordingly. Extensive faulting across the field and the changes in the reservoir conditions between tracer injection and analysis period made the project even more challenging. After 10 years of tracers' injection, an extensive study was carried out to review the initial design assumptions and to fine tune the prediction models. As a result an optimized/focused tracer surveillance strategy was developed and implemented.

The proposed paper tracks an interesting and thought provoking journey of the tracers inside the reservoir that has not only helped reservoir management team to better understand the reservoir characteristics, but it has also identified the gaps in the tracer project design and execution strategies. The indispensable experience gained during the past 10 years, starting from the tracers design, the project execution and the integration of the results, has tremendously improved the learning curve of the ADMA-OPCO and all future tracer surveillance project strategies are designed based on the actual learning from this project.

For a giant heterogeneous field like the one discussed in this paper, the investment return time for a tracer surveillance project can be nerve wracking, which requires patience, careful continuous assessment and adherence to the project plan. Besides sharing the lesson learnt, this paper also explores the added benefits of the tracer studies.
Analysis of Soot Emissions from the Combustion of Diesel Blended with Biodiesel Toward Mitigating Environmental Pollution
Authors: Kareem M. O. , Raj A. , Peña G. D. , Alrefaai M. M.
Published: November 2016

In the attempt to reduce environmental pollution caused by emissions from diesel engines, alternative fuels for diesel have been suggested in this work to be used in suitable combinations with it as blended fuel. These alternative fuels are oxygen-containing compounds, which emit less emissions when used in the engines either alone or in combination with diesel due to the presence of fuel-bound oxygen. This work studies the effect of the use of blends of diesel and biodiesel (derived from neem-oil), on engine emissions. The smoke point test for the blends of diesel with biodiesel in increasing blending proportions from 0 – 30 % was conducted experimentally, according to ASTM D1322 standard. Soot was also collected at heights above the smoke point for the fuel blends, and the changes in the nanostructure and the reactivity of the resulting soot particles, as compared to soot from petroleum diesel, was identified using suitable characterization techniques such as high resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) techniques. Expectedly, these blends provide a notable reduction in the type and nature of the emissions in comparison to those emitted from petroleum diesel. These emissions typically contain soot and an understanding of the changes in the morphology and physical characteristics of the soot formed from the blends in juxtaposition to that formed from the diesel fuel is of interest in observing the effectiveness of the use of these oxygenated compounds in combination with the fuel on the engine emissions. It was observed that the smoke point values increased with increasing percentage of biodiesel in the blend, which indicated a reduction in the sooting tendency of diesel due to the addition of biodiesel. In addition, the results of the characterizations, in addition to the observed reduction in the sooting tendency of the diesel fuel due to the addition of the biodiesel, indicated physical and chemical changes in the nanostructure of the soot particles. Furthermore, these observed changes in the nanostructure of the soot particles were related to the changes in its morphology and reactivity. The results from this work contribute to the understanding of the nature, physical nanostructure, chemical reactivity and morphology of soot particles resulting from diesel fuel used in engines, as well as changes in these properties when it is used in combination with its oxygenated alternatives. Therefore, it indicates a potential avenue for the reduction of the environmental pollution effects of the fuel.
A Novel Integrated Approach for Multistage Transverse Fracturing in Up-Dip Heterogeneous Reservoir of Western Onshore Basin, India
Authors: Sharma Vinit , Pandey Yash , Negi Anil Singh , Bhatt Pankaj , Das Santanu
Published: November 2016

The main objective of this paper is to present a case history of 26 successful Multi-Stage Fracturing jobs performed in 4 horizontal (up-dip) wells drilled in the western onshore field of India. A detailed analysis of Frac job design, Stress profile analysis, well placement, exploitation approaches and successful implementation of new completion technology is also addressed.

Detailed stress profile studies were conducted to finalize the azimuth of the well. Placing the lateral section of the well with reference to the stress directions plays a major role in the success and effectiveness of fracturing in enhancing and sustaining productivity. Rock mechanical data was taken from nearby offset wells. The data was extrapolated over a lateral length of ~1000m and an up-dip angle up to 9 degrees. Considering the heterogeneity of formation, Mini-frac and DFIT test analysis were conducted in alternate stages to get the variance in leak-off and permeability throughout the horizontal section of the reservoir.

An exhaustive study involving numerous tests on core and oil samples were conducted including elemental analysis, XRD, SEM, Capillary Suction Time (CST), Non-emulsification tests etc. Observations from the tests confirmed that Pour point of the crude was considerably high and crude was waxy in nature. Mineralogical analysis showed more than 40% of MLIS clays. The inputs from these test results were incorporated in formulating the frac fluid as well as job design. Geoscience studies results were utilized in finalizing the well trajectory and placement. Sensitivity analysis helped in deciding the optimum proppant volume for the stages. Post frac job analysis confirmed achievement of target transverse frac geometry and good conductivity. The same results were also supported by the encouraging production performance from the wells.
A New Tera-Hertz THz Imaging Device for Multiphase Flow Metering
Authors: Saied Imran , Meribout Dr. Mahmoud , Hosani Esra Al , Kalra Mohit
Published: November 2016

In this paper, a new FPGA-based THz imaging device for real-time multiphase flow metering is proposed. The overall system consists of a THz source and a THz camera within which a stainless steel-flanged Teflon-made cylindrical probe is provided to carry the multiphase flow. Hence, the system acts like an X-ray-based device but has the advantage of having non-ionizing waves which makes it a safer alternative. In addition, the system provides a much informative indication about the flow by capturing its two-dimensional image in real-time and without the requirement of performing the time-consuming and errorless-free image tomography techniques. The THz camera consists of 64 × 64 pixels which represent the actual accumulated dielectric of objects value within a projected line in the space. The camera provides the pixel values via a digital video bus (USB port) to an FPGA board for real-time video processing and display. The video processing consists of a cascade of consecutive tasks which include image filtering and histogram, feature extraction and counting (for phase fraction measurement), in addition to block-based motion estimation (for flow rate measurement). This constitutes a breakthrough in the field of multiphase flow metering since this task can take full advantage of the mature and advanced techniques achieved in video processing to achieve the most accurate and informative multiphase flow measurement. Extensive experimental tests were successfully carried out on the developed device using various samples with different concentrations of water and air. Hence, an accuracy of 90.2% for the multiphase flow measurement, with a total processing time of 110 ms/frame were achieved. This can be improved even further if a more advanced FPGA featuring high speed clock, in addition to more advanced video processing algorithms are simultaneously used.
The Performance of Water Injection Wells Equipped with ICD Completions in One of the Giant Offshore Field, Abu Dhabi
Authors: Channa Zohaib , Khan Muhammad Navaid , Iwama Hiroki , Husain Ali , Al-blooshi Jamal R. , El-Sayed H. S. , Nofal Salman F. , Al-feky Mohamed H. , Ahmed Fazeel
Published: November 2016

As a part of the effective reservoir management in commingled water injection wells crossing different formation layers with varying characteristics (Thickness, permeability, reservoir pressure etc), ICD completions in combination with open hole have successfully been deployed in ADMA-OPCO in more than 10 wells since 2009 to control water injection in high permeable formation and ensure uniform fluid sweep. ICDs were placed against high permeable formation for controlling injection rates while keeping open hole in lower permeable formation. Production logs (PLT) were run in most of the ICD deployed wells to quantify the injection rates across ICDs and open hole section. Based on production logging results, down-hole completion design changes were considered and incorporated in newer wells as a part of continuous improvement. Case histories of ICD installations across high permeable zones showed the technique helped in better injection distribution and reservoir performance improvement. The aim of this paper is to discuss the performance in water injectors with different ICD completion configurations, improvement in injection distribution in different permeability reservoirs, lesson learned during completion running operation.
Successful Integrated Reservoir Management Leads to Doubling of Production: A Case Study of Upper Burgan Reservoir, Raudhatain Field, Kuwait
Authors: Chellappan Suresh Kumar , Al-Hajeri Nasser Saif , De Santanu , Safar Ahmed
Published: November 2016

In the current and future scenario of increasing demand for hydrocarbons, Multi-Disciplinary Integrated Reservoir Management team is the key to achieve maximum production rates and ultimate recovery. In Raudhatain Upper Burgan reservoir production started in 1959 with initial reservoir pressure of 3850 psi. Decline in reservoir pressure with sustained rate of production indicated weak aquifer support and initiated water injection during the year 2001 with three flank injectors. Production rate was sustained at 30 to 35 MBOPD for long time and it was decided that to go the next level of production and to meet KOC's strategic production target.

Various alternative pressures – production plans were scrutinized by the multi-disciplinary team consists of Geologists, Reservoir Engineers, Petrophysicists and Petroleum Engineers and identified bottlenecks, constraints and action plan to address the problems and to accelerate the production. Some of the bottlenecks to accelerate the production were decreasing pressure, unavailability of required volume of water for injection, delay in commissioning of effluent water injection facility and low productivity of flank wells with viscous oil. The integrated Reservoir management team initiated number of projects to increase the productivity like Paradigm shift in drilling practice by way of drilling Horizontal, Multilateral wells and completing with ICD's for better production and injection sweep efficiency. Liquidated the sick wells with no potential in any other Reservoirs (Multiple Reservoirs) are identified for Horizontal Sidetracking to sweet spot areas. Decreasing Reservoir pressure and Voidage Replacement Ratio has been addressed by changing the water injection strategy and aligning the injectors in right areas.

The results were rewarding as the production rate doubled from a sustained level of 35 MBOPD to more than 70 MBOPD in a span of 3 to 4 years. The initiatives taken to convert the producers to injectors resulted in increased water injection volume and doubled the Voidage Replacement Ratio.

This paper presents the details of Integrated Reservoir Management team efforts and what are the initiatives and strategic actions taken by overcoming the current constraints to double its production. It discusses the effective Reservoir Management of a mature oil field to enhance and accelerate production.
Learnings From Incidents in Steam Systems
Authors: Nuthanapati Sreekanth , Shenoy Manur Ajith , Miranda Robert , Adel Khalid , Awadhi Ibrahim Al
Published: November 2016

In Oil & Gas plants, steam is supplied to different process units such as turbines & reboilers through piping and is routed on pipe racks. The steam system is encountered with typical problems such as condensate accumulation, hammering, vibrations, condensate discharge, etc. These can cause serious damages to the piping and supporting systems. Such operational and design issues related to steam service can affect the integrity of Plant structures. This paper presents the improvements that are considered in steam lines and their supporting structures which assures high safety and integrity of the system.

Steam traps are provided to filter out condensate and non-condensable gases without letting steam escape from steam pipes. Faulty working of steam traps causes accumulation of condensate resulting in hammering which induces heavy vibration and impulsive loads. The impact loads are not accounted in structure design as their magnitude can't be precisely computed due to its complexity and dynamic nature. These accidental loads can have destabilizing effects on the system such as failure of pipe supports, supporting structure, consequential damage of neighboring pipes etc. Conventional practice of open discharge of steam trap condensate on concrete substructure is another cause of concern.

Comprehensive study of failure of piping & structural systems at different plants was undertaken to identify possible root causes and realize mitigation measures. To address the deficiencies identified and to further enhance safety, various improvement options were studied and optimal solutions to steam system design were finalized. Some of the improvements proposed included positive isolation / blinding of steam lines to avoid condensate build up, removal of abandoned steam lines, periodic condition monitoring of steam traps, installation of automatic Wireless Acoustic Monitoring system for steam traps, design prerequisites for cantilever supports, sampling and testing of supplied structural bolts as a part of QA/QC, routing of condensate drain discharge to plant drainage system. Suggested improvements and recommendations were implemented and no further issues were reported until this time.
The History Matching of Commingled Injectors Through the Evaluation of Horizontal Well Performance in an Offshore Carbonate Oil Field in Abu Dhabi
Authors: Iwama Hiroki , AL-Silwadi Basil Mohamed , AL-Feky Mohamed Helmy , Nakashima Toshinori , AL-Shehhi Omar Yousef , AL-Neaimi Ahmed Khalifa
Published: November 2016

This paper introduces the history matching process of commingled wells and demonstrates how to reduce the uncertainty of the vertical permeability ratio (kV/kH) by analyzing the production logging results of horizontal wells which have been used only for allocation through the evaluation of horizontal well performance.

The field discussed in this paper is an offshore carbonate oil field located to the Northwest of Abu Dhabi. In this field, a lot of horizontal water injectors have been drilled and completed for the purpose of reservoir pressure maintenance. Historically, most of horizontal water injectors were completed as comingled injector covering two layers isolated by thick dense layers. Due to the complexity of the well and the difficulty of well monitoring, the well performance of these horizontal water injectors was not fully integrated into the model history matching process.

The kV/kH ratio is one of the important parameters for analyzing fluid movements in carbonate oil reservoirs. Generally, the value obtained from core analysis results is utilized for reservoir simulation models. In this paper, the effectiveness of analyzing production logging results for commingle wells is introduced as a method for evaluating kV/kH on the simulation model. The end result can reduce uncertainties of kV/kH resulting from heterogeneity of carbonate reservoirs.

It is confirmed that production logging results of commingle horizontal wells are valuable for evaluating kV/kH to be defined the simulation model. They can help to reduce the uncertainty in kV/kH, although there is not enough data for the history matching process.
Improving Efficiency in Rig Perforating Operations by Managing Larger Diameter Gun Strings on Wireline Cable for the First Time in the UAE
Authors: Toki Takahiro , Al Wahedi Khalid , Benygzer Mhammed , Kasem Youssef , Singh Rudra Narayan , Sookram Neil , Cocagne Michael , Banda Maria Eugenia , Klein Daniel Hunter , Wagner Joris
Published: November 2016

After Cuttings Re-Injection (CRI) wells are drilled and cased over the targeted zone, the next step in the process towards finalizing the well is usually perforating the casing. Perforating guns can be deployed with the rig on location or rigless after the production string has been run in the well. Operations with the rig usually offer the benefit of being able to use larger guns with improved formation penetration and larger perforation tunnel size. The extra penetration helps bypass the damaged zone around the wellbore to get into the better permeability of the undamaged formation rock for improved injectivity. The larger perforation tunnel allows more contact with the formation and increased flow area, factors which also help improve injectivity. Rigless perforating generally requires smaller guns which can pass through the tubing, and therefore offer less formation penetration and smaller perforation tunnels. However, one of the major benefits of the rigless operation is the rig time savings, which can often be substantial.

Very good injectivity is a must for CRI wells to manage the large amount of cuttings that will be injected. Large diameter holes in the casing are necessary along with a high shot density for more holes, and 7″ perforation guns were required for the 9-5/8″ casing to achieve these characteristics for injection purposes. When large perforating guns are used, the tubing-conveyed perforating (TCP) technique is usually prefered over cable-conveyed guns because of possible cable damage from shock when the guns are detonated.

The TCP technique often requires more rig time however and usually results in more overall cost than for a wireline operation with a small number of gun runs. Another consideration for the CRI wells is that they are drilled by a new rig with a relatively inexperienced rig crew. Considering rig performance, using wireline for the perforating operation could therefore be more effective in reducing operating time. However, a number of factors have to be taken into account when preparing for perforating using longer, large diameter gun strings on cable, including gun string weight, shock on cable head when the guns are detonated and cable weak points. The shock forces for this case were modeled with special software and the necessary high-strength cable, shock absorbers and weak points were procured for the operation. Rig up limitations also had to be considered to manage the length and weight of the heavy string and a special sequence was prepared and implemented using an on-site crane.

The job was managed safely and efficiently in the single planned run, marking the first time this type of operation has been done in the country and this paper summarizes the process and the efficiency results.
Unique Approach for Subsea Pipeline Design Challenges in Abu Dhabi Shallow Waters
Authors: Selvam Rajendran , Binthabet Hussain A. , Bufalah Salah Jebara , Qambar Najem A. , Azouz Amr M.
Published: November 2016

Several thousands of kilometers of subsea pipelines and cables were installed in UAE shallow waters from 1960's till date; continued expansion can be seen through ongoing and several new projects. During this period many challenges have emerged in subsea pipeline design, installation and commissioning aspects and have presented a major constraint for offshore oil & gas operating companies in the region, affecting both the infrastructure development and the day to day operation in the field. Systematic efforts have been made to identify, assess and consciously resolve these identified challenges attributed to the overall "pipeline system design" vis-à-vis ensuring harmony with prevailing industry practices. Through due diligence and commitment, improved engineering design and installation practices have been developed with utmost synergy and collaboration between the operating companies to successfully overcome these challenges and present a safe and risk-free pipeline system for the production and export of processed crude in this region.
Validation of Formation Pressures While Drilling against Wireline Conveyed Formation Tester in a Carbonate Reservoir in the UAE
Authors: Maalouf Christophe Bassem , Espinoza Irina Bacca , Al-Jaberi Salem , Lyonga Sammy Molua , Haji Latifa Al
Published: November 2016

Historically, pressure measurements have been acquired with Wireline Formation Tester (WFT) tools. In highly deviated and/or lateral wells where tools are drill-pipe conveyed, this can be problematic and add significant expenses and operational risks. Formation Pressure While Drilling (FPWD) measurements minimize operational risks at reduced overall cost and increased operational efficiency. This is particularly relevant in high angle and/or lateral wellbores.

This paper discusses the best practices for acquiring formation pressures with FPWD applied for better understanding of local depletion scenarios. The best procedures were used to obtain accurate reservoir pressure measurements while drilling in a side track section. The pressures were compared with pressure acquired from a WFT in the pilot hole. The comparison was used as a benchmark for the data quality between FPWD and WFT.

Especially with a large scale projects such as new field development planning, it is important to validate FPWD against proven WFT mesurements to ensure data quality is not compromised for cost saving. However, benchmarking two formation testers run at different times with varying mud/drilling conditions needs a good pre-job planning especially if the tolerance is less than 10 psi drift. After consultations with all stakeholders, a logging sequence was agreed upon which optimized logging time, giving the best chance of attaining optimal well-bore conditions for formation testing. Results showed a very good match between WFT acquired in pilot hole and FPWD data acquired two weeks later in the side track section a couple of hours after drilling. The differences between the two measurements were between +0.8 psi and −6.4 psi.
Diagenesis of Mid-Triassic Ghail Formation, Wadi Bih, Ras Al Khaimah
Authors: Guo Yunfei , Ceriani Andrea
Published: November 2016

This study focuses on the Early to middle Triassic carbonates of the Ghail Formation outcropping in Ras Al Khaimah (UAE). A range of different methods, which includes outcrop logging, sampling, petrographic descriptions, fluid inclusion and isotopic analyses has been used to describe the main stratigraphic and diagenetic features of the outcropping sedimentary series. Optical microscopy, Scanning Electron Microscopy (SEM) and Backscattered Electron image (BSE) with Energy-dispersive X-ray spectroscopy (EDS) were used to assess the timing of different diagenetic events (paragenesis), which included dolomitization, physical/chemical compaction, iron oxide formation and late calcite cementation.

Isotope analysis showed two different generations of dolomites, i.e. a low temperature dolostone and a high temperature dolomite cement, which could result from evaporation in a sabkha environment and from burial diagenesis, respectively. Fluid inclusion microthermometry in cements filling vugs proved useful to confirm the mesogenetic (burial origin) of the drusy dolomite cements.
A Giant Reservoir is Talking and We are Listening: Characterisation and Understanding of a Giant Fractured Reservoir in Oman with Extensive Years of Production
Authors: Al-Hadhrami M. , Ferrero M. Boya , Kawar R. , Unal E. , Wahaibi A. , Bazalgette L. , Al-Farsi S. , Khabouri K.
Published: November 2016

This paper discusses the interpretation of historic data for a giant and COMPLEX fractured carbonate, leading to a different understanding of the reservoir's displacement processes, and renewed insights for future development opportunities.

Specifically, the paper describes a comprehensive study to Locate The Remaining Oil (LTRO) and improve the ultimate performance of the field. The study encompassed the integration of recent seismic datasets, BHI (Borehole Imaging) data from over 100 wells, well logs for key wells at different time lapses, core data for different facies, well performance and interference data. Focus has also been placed on understanding the various recovery mechanisms that the field has undergone (water injection and Gas-Oil Gravity Drainage (GOGD) concurrently in different regions of the field). This LTRO exercise has provided insights into the distribution and intensity of inter- and intra-faults and the fracture connectivity between the field units. This warrants clustering the giant field into "development districts" i.e. to move from layer-based development to acknowledgment of vertical communication between layers It has become apparent that the reservoir architecture and fluid flow characteristics in this giant reservoir benefits from a secondary system of background fractures. The future field development concept should target- the matrix blocks with background fractures holding remaining oil for a slow GOGD development.

The study is part of continued efforts to build a centre of excellence in PDO around Naturally Fractured Carbonate Reservoirs, and to help unlock reserves in PDO's extensive portfolio of NFR (Naturally Fractured Reservoir) Carbonate fields.
The Effectiveness of Silicon Dioxide SiO2 Nanoparticle as an Enhanced Oil Recovery Agent in Ben Nevis Formation, Hebron Field, Offshore Eastern Canada
Authors: Ortega Daniel J. , Kim Han Byal , James Lesley A. , Johansen Thormod E. , Zhang Yahui
Published: November 2016

The Hebron Project is the fourth major development offshore Newfoundland and Labrador, Canada, with an estimated 2620 million barrels of oil and a target first oil in 2017. The Ben Nevis reservoir accounts for approximately 80% of the crude oil with an estimated 30% recoverable. Hence, enhanced oil recovery (EOR) requires attention now even before production starts. This research evaluates the effectiveness of silicon dioxide (SiO2) nanoparticles as a water additive to enhance oil recovery in the Ben Nevis Formation, Hebron Field. The experiments involved two main steps: measuring interfacial tension, and determining the wetting character of the rock surfaces. Unlike previous research using SiO2 nanoparticles, in this work, the SiO2 nanoparticles are dispersed in seawater instead of deionized water or simple synthetic brine; experiments are conducted at reservoir conditions (Hebron Field: 62°C and 19.00 MPa); and synthetic cores were used that best represented facies of Ben Nevis Formation. A major challenge was forming a stable SiO2 nanofluid in North Atlantic seawater. Since salinity directly affected the stability of the nanofluid, hydrochloric acid was used as a stabilizer. Interfacial tension (IFT) was measured for SiO2 dispersed in deionized water, as well as stable nanofluids with SiO2 concentrations of 0.01, 0.03, and 0.05 wt% dispersed in seawater, to determine the contribution of SiO2 nanoparticle on the alteration of IFT. The contact angles were measured on core plugs before and after aging in 0.01, 0.03, and 0.05 wt% SiO2 nanofluids, to determine whether SiO2 nanoparticles can alter the wettability of the core. The results show that hydrophilic SiO2 nanoparticles are effective water additive for EOR. When comparing IFT experiments with deionized water and SiO2 nanoparticles dispersed in deionized water, the nanoparticles reduced the IFT from 39.70 mN/m to 21.54 mN/m. IFT is also reduced from 21.80 mN/m to 16.61 mN/m in case of experiments in seawater and a 0.05 wt% stable SiO2 nanoparticles dispersed in seawater. The contact angle experiments demonstrate that SiO2 can decrease the contact angle, and therefore make the rock surface more water wet under reservoir conditions. Finally, it is also found that the higher the SiO2 nanoparticle concentration, the higher the wettability alteration.
Reverse Engineering of a Five Stage Centrifugal Compressor Rotor
Authors: Schwab Stephan , Gilardone Dominic , Ayed Anis Haj
Published: November 2016

This paper reports about the reverse-engineering of a five stage centrifugal compressor rotor by a Non-OEM turbo machinery service provider. In order to reach the aim of increasing the lifetime of the rotor, new enhanced material is used for some compressor rotor parts. The paper describes the method to manufacture a new rotor based on a used spare rotor. Furthermore, the results of the numerical calculations – stress analysis, rotor dynamics and flow analysis – are discussed to show how the required performance is achieved and a safe operation is given.

In the first step, the geometry of the complete rotor is captured with a highly precise and portable 3D-Scan device. The scan was performed on the assembled rotor and for all single parts after disassembly of the rotor. Since the scan is performed on a used rotor, a numerical flow analysis and stress analysis are executed to ensure that deviations or washouts of the used geometry have no effects on the performance and the safe operation of the rotor. In addition to that, a rotor dynamic calculation is executed for the rotor with original material as well as for the rotor with the new material. The comparison between these two configurations provides an indication for a safe operation.

The stress analysis shows a high stress level at the fillet radius to the cover plate of the first impeller stages. To decrease the stress level in these areas, the geometry is adjusted. The numerical flow analysis evaluates the flow field in the complete compressor. It is therefore also required to capture the geometry of the diaphragms. The results show that the performance of the compressor is assured. The rotor dynamics of the rotor with the new material show only insignificant differences to the rotor with the original material. After the numerical analysis the manufacturing, assembly and balancing of the rotor will be shortly described in the current paper.

The successful reverse engineering – which was executed without manufacturing drawings and only based on an old/used sample – of a centrifugal compressor including the use of enhanced material by a mid-size Non-OEM company is of substantial benefit to the state of knowledge in the petroleum industry. Commonly practiced in the European market, especially for industrial steam turbines, reverse engineering of turbo machinery equipment – without compromising on quality or performance – is to be considered a major cost saving opportunity for the petroleum industry.