bluuebunny/crossref_metadata_2025 huggingface dataset:
Fracture Characterization by Seismic Anisotropy Analysis at Awali Anticline Structure Bahrain: Case Study
Authors: Abousetta Abdulnaser , Abdulla Mohamed , Barni Sajeda , Pandolfi Daniela , Michel Jean-Marc , Roure Benjamin
Published: November 2016

The Amplitude Versus Azimuthal AVAZ analysis has proved to be an important tool for characterizing fracture distributions and orientations of hydrocarbon reservoirs. This paper is aiming at the application of this tool for characterizing the fractures in Bahrain field reservoirs. Better understanding of faults and fractures distribution is essential to optimize EOR strategy and reservoir management. Regional analysis is possible by looking at faults distribution characterized by structural attributes analysis validated by regional stress and geological information. The investigation at local scale is more cumbersome but an Amplitude Variation with Azimuth (AVAz) method based on azimuthal Fourier Coefficients (FCs) proves to be a simple and powerful tool to characterize fractures distribution validated by FMI data. The anisotropy information was then used to update and improve the reservoir model long production history matching.
Smart Actuators: A Predictive Maintenance Strategy to Achieve Cost-Saving Targets
Authors: Martinelli Stefano
Published: November 2016

End users of the oil and gas industry are seeking increased capital efficiency due to the challenging macroeconomic environment. Seen from a plant operation perspective, this means reduction of total cost of ownership of the assets, through cost saving projects. Operational costs are affected by two main contributors: cost of unreliability (asset failure) and reliability improvement costs. The selection of the right maintenance approach for valves is then critical to achieve efficiency targets set by the end user and meet optimum point of total costs.

Predictive maintenance strategy is based on the assessment of the critical valves condition by means of performance datas, nonintrusive testing techniques and visual inspection. Analysis of the valve condition-monitoring datas on a continuous basis is useful for planning and scheduling maintenance/repair in advance of catastrophic or functional failure.

Failure always comes unexpected and costs of such event will include: production losses, temporary resources allocation (emergency management), quick mobilization of suppliers, risk management. How cheaper and lower risk it would be to plan repair or replacement activities during a scheduled shutdown! Smart actuators and communication networks are main enablers of predictive maintenance techniques applied to actuated valves; the diagnostic features of such intelligent devices support end users to monitor the condition of valves, collect and analyze data while the plant is up and running, saving time and resources, anticipating issues in order to improve availability of their critical assets, minimizing cost of unreliability.

The main target of this paper is to educate the reader about the importance of predictive valve maintenance through smart actuators in order to achieve cost-saving targets.
Sucker Rod Pump Production Optimization Via Intelligent Real Time Surveillance In Joint Operations – Wafra Field Illustrated Through Case Examples
Authors: Bahbahani Baqer , Attia Adel , Jagannathan Rajaperumal , Heshmat Kareem , Mohamed Assem
Published: November 2016

The oil and gas industry is applying smart techniques to monitor, manage, and optimize the assets in a safe manner. Real-time surveillance for 450 instrumented sucker rod pumps allowed instant detection of problematic wells and provided data for smart analysis. This manuscript focuses on enhancing production in sucker rod wells by improving the surface pumping unit and downhole efficiency to decrease operating cost, minimize deferred oil, and run at optimum condition.

The intelligent field enabled teams to collaboratively make decisions that maximize profit and to understand their short- and long-term impact. The availability of historical and the real-time data for 450 instrumented sucker rod systems provided the opportunity to identify abnormal well performance in many terms, such as high gearbox, structural load, and overloaded motors. Having a database with analysis workbench capabilities helped in further investigating well potential versus current load capacity. For wells with high loads and high well potential, it was a challenge to make the best production optimization decision for each well based on their current running conditions.

To identify candidates for production optimization, the surface pumping unit, the downhole equipment, and the performance of each well were evaluated. Of 450 wells, 57 wells were classified as: High-potential wells running at high sucker rod pumping unit load and requiring upgradeHigh-potential wells running within limitations of the sucker rod pumping unit and running parameters need modificationWells running at optimum conditionsWells pumping at optimum well productivity using a bigger sucker rod pumping unit than required

For production optimization and cost saving, it was decided to use the available sucker rod pumping units to swap the overloaded units with the low-load units. It was recommended to keep continuous optimization for automated wells (wells running with variable speed drive). The remote control availability helps in applying changes of the running parameters in a safe manner. The estimated oil gain for the 57 wells is 1,500 barrels of oil per day according to the simulation executed.

Smart sucker rod pump optimization in the neutral zone between Kuwait and Saudi Arabia for the first time enabled real-time surveillance, data storage, instant analysis, and diagnostics reporting in which problematic wells were identified, solutions were recommended, and necessary actions were applied.
Micro Dogleg Detection with Continuous Inclination Measurements and Advanced BHA Modeling
Authors: Menand S. , Mills K. A. , Suarez R.
Published: November 2016

Micro doglegs are a natural effect of any vertical or directional well that can explain a wide variety of down hole problems, from additional torque and drag to an inability to run completions. These doglegs are inherent to the rock drilling process and can generate borehole spiraling in vertical sections or slide-rotary pattern when using steerable mud motor in horizontal sections. Standard surveying every 95ft or so cannot detect these micro doglegs and only gives a partial look at the actual well path. This paper presents the results of a case study showing how accurate downhole measurements combined with advanced drill string modeling can detect borehole tortuosity and better quantify the down hole drilling efficiency.

A trajectory prediction model able to calculate the inclination and azimuth each foot or so has been developed to estimate micro doglegs using standard surveys, bottom hole assembly (BHA) data and steering parameters. In the demonstrated case, a slick motor assembly was used to drill a horizontal well in a single run. The predicted trajectory was then compared to actual continuous inclination data gathered by the measurement while drilling tool during drilling and showed a good match between the predicted trajectory and the actual drilled trajectory. Transitions between sliding and rotating modes are highlighted by micro doglegs and downhole forces, such as bending moment close to the bit, are well reproduced by the model.

This new methodology combining downhole data measurements with drill string modeling analysis highlights the potential for drilling optimization and wellbore placement. Having a better definition of the well path is very critical for torque and drag analysis and wellbore placement.

This paper presents for the first time a comparison between continuous survey measurements and computer modeling to highlight the importance of micro-doglegs in evaluating drilling performance.
Numerical Simulations on the Applicability of Multiphase Down-Hole Twin-Screw Pumps MDA in Offshore Oil production
Authors: Alwan A. A. , Dominik W. R , Lewerenz J.
Published: November 2016

Multiphase pumping technology is continuously emerging in the oil industry as solution for oil and gas field production where limitations with conventional pumping systems occur.

This paper presents the recent research on the application of a new multiphase down-hole twin-screw pump on the base of reservoir and production simulations of an offshore oilfield.

The simulations revealed that the deployment of the multiphase down-hole pump in galleries in two phases of tail-end production led to a positive impact in well and reservoir performance compared to natural flow as originally achieved in the field production history. The down-hole pumps extended the well life, added incremental oil and improved the ultimate recovery.
Downhole Sand Ingress Detection Using Fibre-Optic Distributed Acoustic Sensors
Authors: Thiruvenkatanathan Pradyumna , Langnes Tommy , Beaumont Paul , White Daniel , Webster Michael
Published: November 2016

Sand production remains a key technical challenge in many reservoirs where formations comprise of weakly consolidated sandstone. Sand control completion equipment is typically installed to prevent sand from entering the well. However, in cases where the sand control is ineffective due to installation flaws/defects, high sand production may occur often requiring choking back of wells and resulting in significant hydrocarbon production losses. An effective remediation requires identification of locations of sand entry. However, there is currently no proven technology available in the market that accurately identifies downhole sand ingress locations in real-time. In this paper, we present results from a new technology solution that addresses this challenge by using in-well conveyed fibre optic distributed acoustic sensors (DAS) for the detection of sand ingress zones across the reservoir section throughout the production period in real time. The technology employs a novel signal processing technique that isolates and extracts acoustic signals resulting from sand ingress from background flow and instrumentation noise in real time. The new processing architecture also addresses the "big-data problem" that currently hinders DAS technology uptake through use of intelligent feature-extraction techniques that reduce data volumes at source (by several orders of magnitude). The technology feasibility has now been verified both through flow loop experiments and through multiple field trials and has been successfully used to inform the first targeted sand remediation in a BP production well.
Development of Robust ICD Designs to Provide 30 Year Life by an In-Depth Qualification Program
Authors: Edmonstone Graham F. , Kofoed Curtis W. , Mayer Christian S. , Troshko Andrey A. , Jackson Matthew S.
Published: November 2016

Following a premature failure of an ICD liner in a pilot ERD well in a giant Middle East offshore oilfield, a thorough investigation, summarised in a prior paper1, 2, was undertaken to understand the failure mechanism. The conclusion of the failure analysis was that high shear flow from the ICDs accelerated tubing corrosion leading to a complete penetration of the tubing wall in the vicinity of the ICDs.

This paper details the subsequent work undertaken to initially review existing ICD designs currently available from the market to deem their suitability to withstand flow induced corrosion. Initial review of current designs led to the need for subsequent development of improved ICD designs, also detailed in this paper, that could withstand flow induced corrosion, as well as accommodate heightened production (400 - 1,600 psi) and stimulation (1,000 - 2,400 psi) differential pressure requirements.

In particular the paper will cover the below areas of qualification, with key outcomes: Engineering design review of existing, improved and new ICDsCFD analysis for flow-induced corrosion hotspot identificationIntegrity testing for production and stimulation scenariosFlow performance and minimum back pressure requirement testingErosion testing of the entire ICD assembly

For any of the designs to be suitably qualified, they had to systematically and successfully pass the aforementioned five areas, which in summation is believed to be the most in-depth qualification program undertaken in the industry to date. It has also likely developed the most robust ICD designs to date affording the ability to operate under heightened production and stimulation conditions while still providing the required 30 year life for use in a giant Middle East offshore oil field.
Injectivity Enhancement From Back Flowing of Water Injectors
Authors: McNeilly K. , Al-Shamsi A. R. , Khan M. N. , Al-Blooshi J. R. , Husain A.
Published: November 2016

Allowing a water injector to flow (also known as "backflowing") for periodic periods after injection has been identified as an opportunity to quickly and cheaply improve injection rates. Data collected from 21 water injectors in a giant offshore carbonate reservoir in the Arabian Gulf indicates an average injectivity improvement of 53% can be achieved (equivalent to an average gain of 987 bwpd per well) when comparing the injection rates before versus after the backflow event.

Decreasing injectivity has been seen in some water injectors in the field. The cause of this decrease is suspected to be caused by suspended solids/particulates in the injected filtered seawater causing formation damage or plugging of the perforations. Acid re-stimulations have historically been used to dissolve these damaging particulates to reduce the skin and improve the well injectivity. However, the conclusion that will be presented in this study is that backflowing water injectors is an additional tool that can be used in the operational toolkit to remove this near wellbore damage and restore a significant amount of the lost injectivity.

Given the high cost, logistical requirements, and environmental impact of acid stimulations an alternative approach to improve injectivity by backflowing the water injectors was investigated. Backflowing operations have been proven to provide a significant improvement in injectivity while only requiring a short duration, limited operational requirements, and small cost. The periodic backflowing of all water injectors should be considered as an operational best practice for the field in the future.
Public Safety and Sour Gas: A Case Study of Innovations in Public Protection and Emergency Response
Authors: Daher Elie , Ziarati Amin
Published: November 2016

A key Oil and Gas player required hydrogen sulfide (H2S) safety solutions for their project in Iraq. The operator had planned a drilling operation on a rig with a high potential concentration of H2S. They realized that they needed to protect and secure two communities that consist of more than 1500 homes near the drilling site from a potential gas release. The mountainous location and tough winters required a reliable, portable and robust detection and communication system that would work in extreme weather conditions with temperatures ranging from -15°C to 52 °C. The two villages were located 5km from the worksite. The operator needed to make sure the villagers are notified of any gas readings that may pose hazards to the communities.

A cutting-edge community protection solution was implemented composed of several gas and environmental monitors linked together to control the conditions within the EPZ. The innovative perimeter monitoring solution allowed environmental conditions to be monitored online in real-time. Due to difficult terrain conditions, boosters were deployed to enhance the connection between the perimeter monitoring system and the base station.

Radio-frequency (RF) and web technologies were integrated into each platform to enable real-time transmission of data to the base unit. From the base unit, the stored data is the uploaded to a global server. This was designed in such a way to give the operator a comprehensive understanding of all the stored information.

The use of a proprietary SCADA system provided a reliable and accurate data log which could be stored and accessed online. Notifications on impending low battery life, wind speed, and direction, temperature and gas readings were provided on a real-time basis, thus helping the operator to make informed decisions to protect its assets and the community, prior, during and post any event.
A C02 Foam Conformance Pilot in US Gulf Coast Region
Authors: Chabert M. , D'Souza D. , Cochran J. , Delamaide E. , Dwyer P. , Nabzar L. , Lacombe E.
Published: November 2016

The use of foams for gas floods conformance control attracts a renewed interest in recent years. Nowadays, despite the low oil price environment, some foam EOR projects remain active both at lab and pilot scale. Indeed, such applications have the potential to not only improve the oil rate, but may also reduce costs associated with gas injection and cycling. In other words, foam can increase gas injection efficiency both in terms of oil production and of gas consumption.

In this paper, we describe the design of a dedicated foaming formulation and its application in a CO2 foam pilot in a CO2 flood in the US Gulf Coast. The main hurdle for formulation design was the use of a high salinity and hardness production water for chemicals injection. Our experimental approach to overcome this challenge was based on successive steps, comprising automated solubility evaluation of multi-component formulations, adsorption measurements, foam stability evaluation and finally corefloods in reservoir conditions. Following this lab work, we carried out the foam injection pilot on a 40 acre, 6-well flood pattern consisting of three injectors and six producers. Conformance rather than indepth mobility control was targeted, and a relatively low foam volume representing 1% pore volume of the pattern was thus injected. The treatment was applied as three alternating slugs of aqueous foaming solution and CO2 over a period of four months, with the aim of generating foam in-situ in the near- wellbore area.

Strong foam formation in the near-wellbore was evidenced by a strong drop in CO2 injectivity after each surfactant slug. Injectivity then slowly recovered, with a slower recovery as a function of the slug number, indicative of foam propagation deeper in the reservoir. Injection logs showed an efficient diversion of CO2 from thief zones to previously poorly swept reservoir intervals. On the production side, although much less CO2 was injected, oil rate was relatively constant, exhibiting little decline. We interpret this as a consequence of the injected CO2 flooding new reservoir zones with higher residual oil saturation. Overall, the strong decrease in CO2 consumption at a relatively constant oil rate translates into a noticeable increase of the injected CO2 efficiency.

This paper describes the formulation design and the foam pilot implementation in challenging conditions, in particular with regard to salinity and hardness of the available injection water. It qualifies foam as a straightforward, low risk conformance method. Indeed, besides potential increases in oil rate, the enhancement of CO2 injection efficiency demonstrates the success of this application.
Development of a Giant Carbonate Oil Field, Part 3: How to Build Enhanced Oil Recovery Development Plan Aiming for 70% Recovery
Authors: Kumar Jitendra , Nakashima Toshinori , Draoui Elyes
Published: November 2016

The considered giant carbonate field is located offshore Abu Dhabi and has 50 years of production history through a series of pressure-maintenance methods. Chronologically, the implemented development approach includes gravity-driven dumpflood water injection, peripheral water injection, and immiscible crestal gas injection and a review of these methods is discussed in Pavangat et al., 2015. Since, the historical pressure maintenance methods are approaching its limitation in sustaining the production; a gradual migration towards sweep-oriented pattern development is required to further extend the plateau and is discussed in Nakashima et al., 2015. The pattern-based Improved Oil Recovery (IOR) not only extends the plateau and recovery but also set the stage for future enhanced oil recovery (EOR) development plan aiming for 70% recovery. This paper describes how a gas-based EOR development plan following the IOR plan was built, in an integrated manner, addressing the gaps and risks from core scale to field scale.

The integrated development plan consists of (a) review of past gas injection pilots, (b) injectant screening based on experimental results, (c) injection scheme selection to maximize the recovery, (d) configuration of the EOR pattern, (e) EOR application timing and rate optimization considering interaction with current development plan, and (f) investigation of surface facility requirements for EOR development.

A sector model study was done, using inputs from the SCAL and PVT experiments, for the screening ((b) and (c)) using the past pilot review (a). Learnings from the sector model simulation is deployed to the full field EOR application by dividing the field on the basis of maturity to water flood and historical development footprint, respecting the simplicity in EOR application without jeopardizing the ongoing production. Through simulation exercises, an integrated EOR plan was built ((d) and (e)). The proposed EOR plan efficiency is evaluated through full-field reservoir simulations, which takes practical drilling plan, well completion types and surface facilities constraints.

The simulation results demonstrated that the proposed plan (a) can recover oil without bypassing remaining oil, (b) can achieves 70% recovery based on selected gas, (c) is vigorous in terms of well count and well-head tower, and (d) utilizes the available surface facilities resources at maximum. The methodology used to design and evaluate the EOR development plan is applicable to other similar fields.
ESD Integrity Management - An Innovation in ESD Proof Testing
Authors: Chitnis Abhijit
Published: November 2016

IEC 61511 requires periodic proof testing of SIFs to demonstrate the correct operation of the loop elements based on Safety Instrumented Function (SIF) design criteria to maintain Safety Integrity Level (SIL) ratings. Proof test serves three primary purposes within the safety lifecycle:

To catch and overcome the failures in the system. To validate SIF integrity and reliability To record and classify failures in a consistent manner to support future analysis.

Challenges with implementing a new or modified approach to testing of Safety Instrumented System (SIS) instruments include issues such as education of participants, integrating the new proof testing procedures with the current maintenance plans and schedule, and documenting failures identified outside of testing. It is critical to create an implementation plan that deals with these challenges ahead of pushing SIS proof testing to facilities. This paper will:

Identify methods to achieve maximum % proof test coverage Proper planning and scheduling Review guiding principles upon which proof tests be developed.
Innovation - The Road Ahead
Authors: Siddiq Shafnas , Kindi Asmaa Al , Yahmadi Amal Salem , Rebello Sylvester , Rayssi Afra Al , Mallo Joshua Frial
Published: November 2016

Innovation in extremely simple words can be described as the deviation from the normal. But sometimes in our everyday efficiency driven work environment we are unable to devote enough time or attention to challenges that need creative thinking and innovative solutions. Another roadblock towards this deviation is connecting the talent which is sometime missing due to distance, environment and silo ecosystem. Organizations driven towards innovation try to overcome these roadblocks by approaching innovation in a structured manner and develop robust collaborative ecosystems supported by processes and technology.

This paper elaborates upon a combination of process and technology that can be deployed in organizations to use collective experiential knowledge to transform theoretical concepts into reality to have a positive business impact. In GASCO we use two specific approaches to drive innovation: Knowledge Café and Ideas Oasis.

Knowledge Café is a brainstorming approach that brings together group of experienced employees with a common understanding of specific challenge to have an open and creative conversation and arrive at solutions to resolve the identified challenge. The knowledge café sessions are divided in two parts, the first part is a quick overview of creativity that will set the momentum for the team, followed by tackling the actual challenge. The way it is structured, allows the participants to not only get an understanding of the subject, but also a process that will be followed in their regular work to think out of the box to tackle their challenges.

Ideas Oasis is GASCO's online ideation system that helps to capture ideas from employees and turn them into business value. It helps us to manage the process from idea creation, evaluation, approval, to implementation and reward.
Finite Element Analysis of the Installation Process of a Corrosion Protective Kevlar Reinforced Liner
Authors: Barsoum I. , Dymock J. , Walters R. , Seibi A.
Published: November 2016

Internal corrosion in pipelines is a persistent problem in the oil and gas industry. To the conventional rehabilitation techniques used to stop corrosion losses and prolong the life of the pipeline uses an internal lining system to isolate the corrosive medium from the host pipe's inner surface. To overcome many of the shortcomings of the conventional lining technologies, recently Kevlar reinforced flexible polymer composite liner has been developed. The installation of this flexible liner takes place in several stages and it is of interest to understand the mechanisms behind the installation process, and more specifically determine the forces and stresses at each stage of the installation process. Hence, the objective of the current study is to build a non-linear finite element model to simulate the full installation process of this new liner. The FEA model is further validated with physical tests, making it a reliable tool for simulating the entire installation process of this liner in an arbitrary pipeline network.
Reducing the Miscibility Pressure in Gas Injection Oil Recovery Processes
Authors: Rommerskirchen Renke , Nijssen Patrick , Bilgili Harun , Sottmann Thomas
Published: November 2016

In gas flooding EOR applications the injection pressure plays a significant role. It has to be higher than the minimum miscibility pressure (MMP) for a fully miscible flood to obtain the highest oil recovery, since the swelling, and consequently the efficiency of a flood, strongly depends on the miscibility of the residual oil and the recovery fluid. Poor miscibility leads to poor recovery. On the other hand the injection pressure must not be higher than the reservoir fracture pressure to avoid the creation of high thief zones in the formation. The addition of proper additives to the injection gas can reduce the MMP significantly.

Using a pressure resistant sapphire cell firstly the solubility of different additives in the gas at common reservoir conditions was determined. The compatibility of the additives with CO2 is needed to be ascertained first in order to identify compounds that enable an easy co-injection of the additive within the flow of the CO2. Then the miscibility behavior of the gas and a model oil was studied and the change of the miscibility pressure in the presence of chosen additives was investigated. Phase behavior studies at typical reservoir pressures and temperatures show the miscibility behavior of the fluids and the effect of the different additives on the mutual miscibility.

It was proven that the minimum miscibility pressure can be lowered significantly by the choice of an appropriate additive. Through determination of phase diagrams it is shown how the miscibility gap between crude oil and CO2 can be decreased, thereby going from immiscible or multi-contact miscible to fully miscible conditions. Adjusting the MMP broadens the pressure range of high sweep efficiency that is limited by the formation fracture pressure as the upper and the MMP as the lower limit. Thus, conditions can be created at which the reservoir pressure leads to fully miscible floods.

Using an appropriate additive can lead to an improvement of the miscibility behavior at given reservoir conditions and make it more favorable for a CO2 EOR process. A former near-miscible or even immiscible application can become a miscible flood. By this the sweep efficiency is maximized and the recovery rate is highest. The parameters that define an economic reasonable gas flooding application now comprise a larger number of reservoirs due to the improved miscibility of crude oil and injection gas.
Successful Real-Time Modeling of Wellbore Hydraulics Using Rheology Obtained According to API Recommended Practice 13D
Authors: Sindi W. , Prohaska-Marchried M. , Thonhauser G.
Published: November 2016

A deterministic method for standpipe pressure calculation in real-time using rig sensor data is presented. The main achievement is the development of a method for modeling wellbore hydraulics with satisfactory accuracy, despite lack and inaccuracy of information about the drillstring components. Exclusion of calibration makes the model more robust and lets the operator know the actual state of the model, at all times.

The methodology is based on dynamic geometrical representation of the wellbore-drillstring system, which is used to calculate wellbore hydraulics, utilizing analytical formulae, including the rheological models Power Law, Bingham Plastic and Herschel-Bulkley, as formulated in the API Recommended Practice 13D. The mud rheology is measured to this standard, i.e. measurements are taken at atmospheric conditions and temperature and pressure effects during drilling operations are neglected. The model accounts for changes in the pump rate and axial movement of the drillstring by means of real-time sensor data, including flowrate as well as bit and hole depth MD.

To validate the model, it was tested on 500 hours of recorded rig sensor data pertaining to drilling of the intermediate or production section of 4 wells using water based mud, and one deep-water HPHT well using synthetic based mud.

It was found that standpipe pressures are predicted with good accuracy for conventional drilling operations, when using water based mud, for both vertical and horizontal wellbores. The deviation between measured and predicted values was in the range of 0-10 bars. Short-term trends for measurements and predictions correlated very well. Further, it was observed that a single measurement of mud properties at the beginning of drilling operations enables sufficiently accurate modeling, even for several subsequent days of operation.

Modeling of the standpipe pressure of the HPHT well was found inaccurate, but modeled and measured data shared the same trend. Consequently, the mud shear stress increase due to downhole temperature and pressure conditions must be accounted for when modeling HPHT wells.

It is concluded that for drilling with water-based muds, the approach yields good results, despite incomplete information regarding the mudmotor and drillpipe tooljoints, and ignoring the temperature and pressure effects on mud properties.

Successful realization of real-time modeling of wellbore hydraulics is achieved through implementation of classical rheology models in an algorithm that understands drilling operations from rig sensor data, for water-based muds, without calibration. Workarounds concerning lack of data for tooljoints and the mudmotor are discussed and their corresponding errors are addressed. Beside the standpipe pressure, byproducts such as ECD, annular cutting velocities and flow regimes along the wellbore are determined in real-time.
A Comparative Study on the Performance of Acid Systems for High Temperature Matrix Stimulation
Authors: Ameri A. , Nick H. M. , Ilangovan N. , Peksa A.
Published: November 2016

This study presents a comparative analysis on the performance of acid fluid systems, which are commonly used for high-temperature (>150°C) carbonate matrix stimulations. The comparison is based upon the key factors including ease of implementation, corrosion and operational costs, and performance assessment in terms of improving well deliverability. Moreover, core and field scale numerical simulations are performed to examine the rock matrix acidizing behavior under different reservoir conditions. The main variables are acid types, temperature, and injection rate. Results underline the conditions under which optimal stimulation concerning permeability and length of treatment is attainable.

According to results, a stand-alone stimulating fluid of glutamic acid diacetic acid (GLDA) shows the lowest corrosion rate followed by methanesulfonic acid (MSA) and hydroxyethyl ethylenediamine triacetic acid (HEDTA) under high temperature conditions. In the absence of corrosion inhibitor, GLDA gives the lowest results in terms of corrosion for 22Cr and 13Cr steels. Moreover, acid response data revealed that GLDA has the lowest optimum injection rate when compared to other acids considered in this study. Our simulation results show that the penetration depth (acid front) of acid is highly affected by the radial flow characteristics in field scale simulations, as the penetration depth is not linearly correlated to the volume of acid injected.
Drilling Performance Automation Introduction in Middle East Asia
Authors: Sadhwani Khushboo , Sanderson Martin , MacFarlane John , Ibrahim Sameh , Garcia Jorge Navarro
Published: November 2016

To attain maximum Rate of Penetration (ROP) with a process for systematic performance improvement for a given; Bottom Hole Assembly (BHA) and a Bit design is a big challenge. Maximizing ROP includes minimizing the time to drill the well and simultaneously minimizing the exposure time for unsealed formations. In order to provide a solution to this critical issue, schlumberger software that defines optimal ROP was deployed to various fields in Iraq, Kuwait and Abu Dhabi.

This paper presents an integrated multidisciplinary process developed to successfully implement the software in the various hole – size section of a well. The Software application contains a Detournay model of the PDC bit cutting action, in conjunction with automated off-bottom calibration routines and changepoint technology to continually fit the model to real time drilling data, allowing automatic identification of formation change. We were able to achieve the highest ROP with the most efficient mechanical specific energy, and drill with the correct balance between RPM (Rotations per Minute) and WOB (weight on Bit) for a specific formation – thereby reducing the waste of energy owing to inefficient drilling parameters.

Drilling parameter recommendations were made in Advise Mode, in which recommendations were passed to the driller on the rig floor for him to execute those. The next phase of implementation is to move to Control Mode, which means the target parameters will be sent directly to the rig control system. Implementation of the workflow helped to improve the on bottom ROP. This improvement consequently resulted in savings of up to several days. This workflow will be implemented across all the future wells in the field and across all applicable hole-sizes of the wells.

Using this Workflow, engineers across various disciplines successfully integrated the simulations and modeling during the design phase of a BHA and bit. Information on the Lithology along with the designed BHA/bit was used as an input for the software to help generate the best fit drilling parameters. The software-recommended drilling parameters were then executed and monitored in real time while drilling. The workflow also provided room for continuous improvement by using the lessons learnt and best practices implemented while drilling as an input for the next run of the software. This closed-loop workflow has consistently shown improvement across various fields and made tracking and improving drilling performance fairly automated
Photo Realistic 3D Cloud of Points of Subsea Structures in Utilizing Rov
Authors: Shehhi Saif Al , Sayed Talal A , Hammadi Hassan Al , Mukhmari Hisham Al , Dhanhani Khalfan Al , Kallinkil Shammas
Published: November 2016

In the oil industry it is always challenging to visualize a full subsea structure or pipeline with precise as built/ as found dimensions or information due to limited visibility underwater and limited accuracy of underwater positioning. But wouldn't it be much easier if you can visualize underwater with same accuracy and details as onshore.

Fortunately Photo Realistic 3D Cloud (PRC), a cutting edge innovative technology have allowed to scan complete structures underwater to create a 3D Cloud of millions of points presenting the as-built of the scanned structure, giving very accurate measurements more than 1/1000 (ex: 1mm accuracy in a 1m measurement)Using breakthrough advanced optical sensors and mathematical disciplines.

Adopting this technology along with driverless ROV inspection on our aged critical subsea structures, in ADMA OPCO, has allowed obtaining comprehensive inspection data, much superior to typical diver inspections, along with precise 3-Dimensional overview of the structure like never before.

This enabled us to locate defects, as found underwater on to a 3-d model of the structure with dimensional accuracy making it easier for the engineering team siting on-shore to assess condition of the structure like never before. 3D model also severs as a record for future reference and allows a freedom to have a virtual mockup of the mitigations required on the structure. This means future site visits are minimized, saving substantial cost and time.
Empowering Knowledge Management by Human Engagement
Authors: Almaghaslah A. M. , Alsaglab W.
Published: November 2016

A modern approach to knowledge management is proposed to resolve one of the major challenges to knowledge management lifecycle, which is people involvement and buy-in. Human motivation and participation directly influence the success of knowledge management activities and outcomes in any organization especially in Petroleum Industry where knowledge has become a cornerstone to daily operations from exploration to distribution. Knowledge management is a dynamic system that organizations use to identify important information, collect it from those who possess it, store it and share it with others. Organizations use such information to improve their processes, customer relations, decision-making, employee morale, performance and profit. This paper proposes a rating and recognition technique that can foster employees' engagement and participation during the knowledge management lifecycle. An automated rating is used for each potential knowledge, which are information that can evolve into useful knowledge to the organization. Rating is based on the summation of points given to potential knowledge entering the lifecycle. Rating based knowledge management lifecycle proposed in this paper links knowledge Phases with knowledge lifecycle actions. Knowledge phases are knowledge creation, knowledge sharing, knowledge structuring, knowledge utilization, and knowledge auditing. Knowledge lifecycle actions are created, stored, shared, used, and reviewed. Helpdesk IT support is used in this paper as a study case where points are granted to potential knowledge when a support case solution is submitted, used for current incident, used for other incidents, resolved an incident, rated by customer, and rated by other support personnel. Effective knowledge management system requires effective participation of knowledge provides. Management should keep knowledge contributions consistent by rewarding knowledge contributors. Knowledge contributors are not only people who help transforming information to knowledge but all members who contribute to the knowledge management system processes such knowledge users, evaluators and others who help the knowledge to evolve. This approach engages employees through positive competition. It motivates employees to provide good quality solutions that can build a knowledgebase.
Less Corrosive, Non-Damaging Iron Sulfide Scale Remover
Authors: Mahmoud Mohamed , Elkatatny Salaheldin , Shawabkeh Reyad , Bahgat Mohamed
Published: November 2016

Iron sulfide scale is a common scale in sour oil and gas wells. It can form in wells producing oil and gas, as well as water injection wells. Iron sulfide scale has different forms based on the iron-to-sulfur ratio. Iron sulfide scale can form in soft forms that are removed easily by acids such as phyrrotite. The scale can also form in hard forms such as pyrite that is difficult to remove by acids. Several attempts have been made to investigate the removal of different forms of iron sulfide. Scale can reduce production and injection rates. At the end, it may completely plug the tubing and the only remedy will be to change the tubing. In the previous work either low pH corrosive fluids were used or high pH fluids with low solubility.

In this study, we introduced a new formulation to remove the iron sulfide scale (especially the hard scale) pyrite form of the iron sulfide. The new formulation has a pH value greater than six with low corrosion rate. Solubility, stability, as well as corrosion experiments, were performed to assess the new formulation. The new formulation is based on a chelating agent and a low pH fluid mixture. Also coreflooding experiments were performed on carbonate cores to assess the performance of the new formulation if it invaded the near-wellbore during scale removal operations.

The XRD of actual scale sample from a gas producer well showed that the scale sample contains 43 % pyrite, 35% mackinawite, and 22% iron silicon compounds. The scale solubility reached 81.6% using the new formulation. The new formulation remained stable for more than 48 hours at a high temperature. The corrosion rate of actual tubing coupons was 0.03 lb/ft2 without using corrosion inhibitors at 125°C/257°F. This corrosion rate within the allowable limit for the industry standards (should be less than (0.05 lb/ft2). Coreflooding experiments showed permeability enhancement using the new formulation which eliminates the risk of using this chemical in scale removal because it will not cause formation damage to the near-wellbore if it invades the formation.
Seeing Your Reflections Revealing Your Data in the World of Point Source, Point Receiver Acquisition - A Case Study
Authors: Maycock Andy
Published: November 2016

Latest evolutions in seismic data acquisition have led to ever increasing improvements in resolution. Finer source and receiver sampling intervals, combined with a move away from receiver arrays have led to the acquisition of the fully sampled signal and noise fields. However, modern acquisition means potentially higher fidelity data is masked by noise requiring exceptionally careful processing and QC.

Unmigrated Qusawhira raw stacks show little or no coherent energy, indicating that data noise content vastly outweighs signal. The Qusawhira processing flow employs successive algorithms to incrementally remove "layers" of noise generated through different mechanisms. Throughout each stage, QC data was broken down into frequency bands to identify noise and signal signatures while gauging the efficacy of processes employed. Selective Pre Stack Time Migrations (PSTM) were run to ensure the integrity of results. Applying the QC methodology outlined revealed unexpected results in several cases.

Acquisition utilizing Geophone Accelerometers (GACs) requires integrating to velocity in order that processes behave as we expect in the velocity processing world. As GAC amplitude response increases at 6dB/Octave, low frequencies are suppressed. Correcting to velocity at a primary stage ensures that low frequency response can be thoroughly assessed. Acceleration to velocity correction on Qusawhira was considered a critical enabler for QC.

In this paper I critically review initial seismic processing steps employed on the recently acquired Qusawhira "S4" survey and illustrate how seismic processing and QC must evolve with the changing nature of our data. Default processing parameters, including those hard coded, should be reviewed to ensure they are appropriate for modern broad band data. QC migrations should be performed at an early stage to confirm diffracted energy is not harmed.
A Novel Approach for Stimulation of Heterogeneous Thin Layered Reservoir in an Offshore Field, Abu Dhabi
Authors: Nofal S. F. , Ahmad F. , Al Alyak A. A. , AL-Mansouri S. S. , Husain A. , Al-Neaimi A. K. , Al-Marzouqi A. A. , Channa Z. , Al Harbi A. B. , Iwama H. , AL-Kasasbeh A. , El-sheikh H. M. , Khemissa H. , Mefleh I. R. , Al-Shamsi M. K. , Hermawirawan L. , Ahmed M. A. , Sarsekov A. B.
Published: November 2016

The current practice of stimulating thin layered carbonate reservoir using conventional acid stimulation techniques (CT stimulation or Bull-heading with CDC) have proven to be ineffective and inefficient as acid tends to propagate more in the higher permeable streaks than low permeable ones. The new approach aims at addressing this problem by increasing the contact surface in the lower permeable streaks to improve its productivity using expanding metal needles.

The vendor has developed a new method for acid stimulation of carbonate reservoirs. The system is encompassed in self-contained subs which are integrated in the open-hole liner and placed opposite to zones of interest. Acid is bullheaded and a large number of small diameter tubes (needles) jet out simultaneously from the wellbore to penetrate the reservoir, creating numerous flow tunnels.

The major application for this technology is to enhance well productivity by connecting the wellbore to the body of the reservoir with as many as 300 flow tunnels. These tunnels drain increase the surface area of the low permeability reservoir layers exposed to flow and hence increase well productivity and reserve recovery.

After completing the stimulation job, a special tool is run to clear the open-hole liner from the metal tubes and keep production ports open to allow accessibility to reservoir for injection or production as well as running of production logging tools for reservoir monitoring.

The new system (4-1/2″) was successfully installed in one well but cleaning of open-hole liner failed due to design problem related to the cleaning tool. Several meetings with vendors have resulted in a wealth of lessons learned on how to improve the system for future application. As such the well is capable to flow but accessibility for intervention is limited.

The initial unloading of the well showed encouraging results from the Fishbone stimulation however later the analysis of flow test monitoring with bottom hole pressure showed decrease in productivity by 35% within short diction of time (~ 2 months). This type of performance has not been seen in other open hole horizontal wells in the field. Also the GOR of the well has increasing trend from the beginning of the production, possibly due to developed communication with top high GOR layer.
Near Infra-Red Based Multiphase Flow Characterization Using Spectroradiometer
Authors: Mah Abdullah , Arsalan Muhammad , Abdullatif Abdullah , Noui-Mehidi Mohamed N.
Published: November 2016

The objective of this work is to establish suitability of using reflected near infra-red (NIR) spectra to characterize and quantify oil and water multiphase flow. Experiments were performed in a laboratory environment measuring NIR reflected spectra of mineral oil and water and their mixtures to identify the distinctive features to compute water contents in representative mineral oil. A spectroradiometer used to experiment with water contamination in mineral oil clearly shows a reflectance of mineral oil at an electromagnetic spectrum range between 1,200 nm and 1,400 nm, and particularly at 1,290 nm to 1,295 nm, successively being reduced with the increasing water fraction in the mixtures. A formula is derived from the best fit quadratic regression method to compute water contents from reflectance of a mineral oil and water mixture in a laboratory environment.