bluuebunny/crossref_metadata_2025_split huggingface dataset:
Feasibility Study of Single Well Tracer Test for High Salinity and High Temperature Reservoirs
Authors: Mechergui Aymen , Romero Carolina , Morel Danielle 
Published: November 2012

Abstract
The single well tracer test SWTT is a well established method to measure Residual Oil Saturation (ROS) in-situ. The large radius of investigation makes the SWTT a well suited method to evaluate ROS reliably compared with other techniques such as coring and logging.
The partitioning tracer is chosen depending on three basic parameters: reservoir temperature, reservoir salinity and live oil partitioning behavior. These properties control the extent of the hydrolysis reaction that takes place during the shut-in time period to generate the secondary non-partitioning tracer. At high temperature and high salinity (HT/HS), the partitioning coefficient Kd and hydrolysis reaction rate Kh can be significantly high, therefore risking complete reaction of the partitioning tracer and loss of test results reliability.
This paper presents a simulation study carried out to evaluate the feasibility of performing SWTT at HT/HS and help the selection of tracers at these conditions. Using experimental design, a series of SWTT numerical simulations were performed to assess the impact of high Kd and Kh on ROS measurement and interpretability of tracer profile.
Results indicate that conventional rules used for SWTT design would need to be modified or adapted in order to have an interpretable signal from the test. The paper presents also the impact of modified shut-in time and drift on the quality of test.
Enhanced Assessment of the Distribution of Organic Matter in Unconventional Plays and Tarmat in Reservoirs Using a New Laser Pyrolysis Method on Core
Authors: Dessort D. , Gelin F. , Duclerc D. , Le-Van-Loi R. 
Published: November 2012

Abstract
Estimation of the amount, the distribution and the quality of the sedimentary organic matter (kerogen) in unconventional plays or tarmat in reservoirs are often key to a proper assessment of the viability technique and/or commercial of these plays. Conventional core- or log-based methods for the evaluation of organic carbon content in various types of formation (e.g. tarmat in reservoir, oil shale and gas shales) are not always satisfactory due to limited resolution and/or non-reliable data.
The acquisition of quantitative and high resolution (centimetric or sub-centimetric) logs of organic carbon on core can be performed, at the labs or at the coring site, using a continuous power laser (LIPS: Laser Induced Pyrolysis System). The technology was first developed to identify the presence of tarmat in carbonate reservoirs where the results impacted the assessment of the reservoir quality, the GOIIP, the presence of permeability barriers and the response of electric logs.
More recently it has been successfully applied on various unconventional studies. For instance it was possible to have a high resolution, accurate and quantitative measurement of total organic carbon in oil shale or gas shale plays. It then allowed (i) to estimate the yield of petroleum which can be produced from oil shale Pyrolysis (ii) to extrapolate, model and map the quantity of the remaining petroleum potential of oil shale deeper in the basin.
This technology will greatly benefit the mapping of these unconventional plays by providing, in particular, a very accurate tool to calibrate conventional well logs with respect to the distribution of the organic matter.
Getting the Right Seismic Data for the Right Characterization Objective
Authors: Paternoster Benoit , Pagliccia Bruno 
Published: November 2012

Abstract
Reservoir characterization is the main target of seismic processing in UAE to guide Field developments. Delivering the data quality required to meet such an expectation is very challenging and difficult to assess objectively.
The basic requirement is that data are processed in a way which ensures that the propagating wavelet has constant properties. Its amplitude, phase and frequency content must be as stable as possible across the area and depth interval of the field. Often, these very same conditions also apply to the incidence and/or azimuthal angle dimensions of the data in order to be able to apply dedicated reservoir characterization workflows.
Common practice is to use seismic-to-well ties for quality control. More than often, they are unstable and parsimonious. Complementary approaches must be used. TOTAL has devised a workflow which helps assess the progress of seismic processing via a set of spatially extensive attributes.
The very first step of this workflow consists in: defining directions for improvement with the interpreter,translating them into attributes relevant to signal characteristics to be quantified.
The second step consists in: setting milestones at the relevant steps of the processing sequence,quantifying the selected parameters with intermediate migrated 3D volumes at these milestones.
When possible, the same parameters have been extracted beforehand from vintage seismic dataset; relative scores can thus be established to monitor the progress of the newest dataset.
Attributes which can be mapped are privileged so that stationarity can be visualized and quantified. At any time during the (re)processing project, they can be confronted with other interpretative information.
Beyond providing objective quantifications, this workflow induces a strong commitment of the interpreter to the processing project at all stages. It yields confidence that the final dataset is fit for purpose and ready for reservoir characterization.
State of the Art of Geoscience and Reservoir Integrated Study for Eor Co2 Pilot Implementation: Example of a Giant Carbonate Reservoir of Arabian Gulf UAE
Authors: Saniez Jérôme , VandeBeuque Sabrina , Ekpenyong Daniel Eyo , Bastos Nadia , Wantong Paterne , Salley Baptiste , Al-Ameri Ammar Faqqas , Al Katheeri Abdulla , Al-Yafei Arafat 
Published: November 2012

Abstract
In the context of global warming, CO2 capture is one of the explored solutions for greenhouse gas emission mitigation. Its injection in oil fields is one of the EOR schemes adapted to the Middle East carbonate reservoirs. A very high ultimate oil recovery is expected with such a process. A proper design to develop full field EOR CO2 is yet to be found and may be fulfilled through the implementation of one or several pilots.
This study of EOR CO2 pilot implementation required a geosciences, reservoir and surface integrated work in order to place it in some robust and promising locations. A static and dynamic synthesis was performed to understand and better capture the structural context of the field and its level of production maturity. The major risks were taken into account for the selection thanks to a complete synthesis of the available data from the core scale to the surface facilities. An adequate methodology was developed to narrow down the possible locations from the field extent (several hundred km2) to only a few squared kilometers of interest. The field was divided in 6 km2 squares (called "locators") for which a two step selection process was applied. In the first step, the geological typology of the reservoirs and their dynamic statuses at the locator level were defined. Then the risks associated to CO2 injection were assessed. At the end of this step, the selected locators were the less risky ones, representating each geological typology. In the second step, the locators were studied more thoroughly with the evaluation of the level of knowledge illustrating the amount and quality of data available; a geological variability study on permeability was also performed on each area. Finally the surface constraints were incorporated to prevent any incompatibilities with the current or future facilities. This second step provided another sub-selection of locators amongst the ones kept at the end of step 1. Overall, the methodology applied allowed to screen the whole field and its reservoirs, and to identify some promising pilot locations representative of the geology, for a given dynamic status, combining high level of knowledge and low risks related to CO2 injection.
Enhanced Dynamic Simulation through Continuous Fracture Modelling of Carbonate Reservoir, Oman
Authors: Al-Harthy Arafa , Al-Sinani Ibrahim , Al-Raisi Muatasam , Al-Azri Saud 
Published: November 2012

Abstract
This paper describes a workflow that was applied to a carbonate field in Oman to derive fracture and effective permeability models that were validated with multiple blind wells and reservoir simulation. The studied block is the largest and most faulted within a field which is currently under water-flood FDP. The study was kicked off with extensive borehole image interpretation. In parallel, several high resolution seismic inversions and spectral imaging attributes were generated as drivers to geological and fracture modelling. High resolution seismic was used to highlight subtle faults. Facies changes were also visible from seismic as seen in cored wells. Sequential geological modelling of GR, density, porosity and SW was carried out and constrained by seismic attributes.
The derived fracture frequency logs were compared against geological, structural and seismic drivers in a process called driver ranking. The results confirmed the role of faults as well as facies being primary controls of fracturing. Subsequently, the screened and cross-correlated potential drivers were carried forward to constrain the fracture models. Multiple stochastic realizations were derived through neural network training and testing and an average model was kept. Final models were validated against hidden BHI data. A new BHI was used to confirm model prediction. Different types of dynamic data in non-BHI wells were also used to validate the fracture models as specific production/injection related issues could be directly linked to presence of fractures. These data include PLT, PTA and tracer tests from which injectivity issues and short circuiting were explained by higher fracture densities and corridors derived from modeling.
Through dynamic calibration, the fracture model was converted to fracture permeability. The fracture permeability is the product of fracture density and a scaling factor derived from history matching. Subsequently, the addition of matrix permeability and fracture permeability will determine the effective permeability. This Keffective was directly used in the reservoir simulator without upscaling since it was part of the same grid hosting the fracture models. The results were encouraging as the simulation was smooth and error-free.
A New Temporary Chemical Packer Enables Efficient Stimulation of a Lower Zone in a HPHT Gas Well
Authors: Al-Ghazal Mohammed , Al-Driweesh Saad , Al-Sagr Abdulaziz , Krishnan Gopi , Jiménez José Camilo 
Published: November 2012

Abstract
As the oilfield industry requires new techniques to generate diversion over large pay zones and easier methods to perform workover operations and perform interventions through Coiled Tubing, research is focused to provide the industry with new technologies that support the growing demand for oil and gas in the world.
Fluid systems that are used to divert acid over large zones and generate non-mechanical isolation on a wellbore have traditionally been viscosified fluids and solid particulates. These substances create (in most cases) a drastic permeability reduction in the near wellbore area of producing zones that are meant to be protected. In operations that require divertion or the generation of a temporary plug, researchers have found that polymer based fluids are best suited, since they create less damage on the formation, and in the case of temporary plugs they can withstand higher differential pressures. The use of such fluids has reduced considerably the need for more complicated deployed techniques, such as mechanical packers, bridge plugs and mechanical diversion techniques.
This paper describes the first application of a polymer gel system in Saudi Arabian gas fields to isolate a section of a payzone on a vertical well, the system's design and operational challenges, and finally, its successful outcome and results. The objective of this application was to place a temporary plug between two producing zones to be able to selectively stimulate the lower zone.
Successful Implementation of Horizontal Multi-Stage Fracturing Enhanced Gas Production in Heterogeneous & Tight Gas-Condensate Reservoirs: Case Studies
Authors: Al-Anazi Hamoud A. , Abdulbaqi Dana M. , Habbtar Ali H. , Al-Kanaan Adnan A. 
Published: November 2012

Abstract
Heterogeneity and tightness of carbonate retrograde reservoirs are the main challenges to maintain gas well productivities. The degree of heterogeneity changes over the field and within well drainage areas where permeability decreases from few millidarcies to less than 0.2 md. Thorough studies have been conducted to exploit these tight reservoirs and not only focused on well performance, but have extended to assure enhancing and sustaining gas productivity through practical applications of technologies. The main objective of this paper is to assess the performance of Multi-Stage Fracturing (MSF) in horizontal wells that were drilled conventionally and did not meet gas deliverability expectation. This paper gives a detailed analysis of well performances, exploitation approaches, and successful implementation and optimal cases to utilize new completion technologies such as horizontal multi stage fracturing to revive low producing gas wells due to reservoir tightness. Placing the horizontal wellbore reference to the stress directions plays a major role in the success and effectiveness of fracturing in enhancing and sustaining productivity.
Several wells have been drilled in tight reservoirs, but could not achieve or sustain the target gas rate. Recently, two wells were geometrically sidetracked targeting the development intervals based on logs of the original hole and completed with MSF toward the minimum stress direction. Open hole logs showed a low porosity development similar of the vertical holes. However, after conducting multiple stages fracturing, both wells produced a sustainable rate of more than 25 MMSCFD that prompted to connecting them to gas plants. Placing these sidetracks in the minimum stress direction helped to create transverse fractures that connect to sweet spots and sustain gas production. This paper provides thorough guidelines for selecting optimal candidates for MSF based on reservoir heterogeneity, proper design and execution of fracturing. It also addresses various components that contributed to the success of both wells, such as reservoir development, workover preplanning, geo-mechanics studies, drilling operations and real-time support, completion operations optimization and best-practices, and performance evaluation of other producers in the field. The paper also includes essential recommendations for development of tight gas reservoirs.
Multiphase and Wet Gas Flow Measurement - It's Not That Simple
Authors: Letton Chip , Hall Andrew 
Published: November 2012

Abstract
During the period since their inception around 1990 until today, multiphase flow meters (MPFMs) and wet gas flow meters (WGMs) have gone from a state of unreliable hardware and questionable answers, to a point where their reliability is becoming acceptable, while providing information that is essential for proper operation of oil and gas production systems.
Because the use of these devices is so much more common today than it was in the past, an illusion may exist in the minds of some that to select, operate, and maintain them at a satisfactory level of performance is straightforward - that they are "plug- and-play" instruments for the modern oilfield. While this remains a prime objective of meter development, it has yet to be achieved.
It is clear that multiphase and wet-gas flow meters have the potential to provide good answers over a broad range of conditions. However, achieving such performance requires more than just a cursory knowledge of upstream measurement. From selecting the right meter(s); in their commissioning, operation, and maintenance; and especially in the use of MPFM and WGM data, an in-depth understanding of many different aspects of the technology must be called upon. Will nature of the well production change significantly over the life of the field, for example moving from a liquid-dominant flow to one that is primarily gas? If the fluid properties of the production change with time, will the meter be capable of accounting for this, or will it require a sample for re-calibration, and is sample collection feasible? Will there be chemicals injected upstream of the meter that might cause confusion in the meter readings?
To adequately address these questions and account for changes in the system, users must track Key Performance Indicators (KPI) through the Life of the Field (LoF). This and other practical questions in the use of these important instruments are addressed and illustrated.
Advanced 3D Geomechanics in a North African Field
Authors: Kartobi Khelil , Ouriri Feriel , Lalili Wassila , Newman Robert , Grelaud Sylvain , Ismail Walid Ben 
Published: November 2012

Abstract
Hassi Messaoud in Algeria has been a major oil-producing field for more than 50 years, with many hundreds of wells successfully drilled. The complex geological structure and varying amounts of depletion mean that 3D geomechanical modeling techniques bring great benefit, particularly in predicting well-bore stability, sanding potential, and hydraulic fracturing. This paper describes such a model for one sector of the reservoir, creating 3D maps of mechanical properties and a 3D stress state that can be updated over time as pore pressures change. Several new methods of applying the results to well design are presented, including the creation of "mud weight cubes" and "sanding potential cubes" to assist with trajectory optimization and mud weight selection, and to provide limits on safe drawdown.
Effect of ‘Artificial Islands’ on Structural Integrity Management of Existing Offshore Platforms-Case Study
Authors: Varikkodan Abdul Gaffur 
Published: November 2012

Abstract
Four ‘artificial islands’ are being constructed in Giant Offshore Field in Abu Dhabi, for the purpose of using as centers for drilling and oil production. ZADCO carried out extensive studies to assess the effect of these ‘artificial islands’ on the existing field facilities, such as offshore jacket platforms and pipelines, as these ‘islands’ would permanently alter the estuaries / topographies of the offshore fields. Studies clearly established that these ‘alteration’ does influence the long term / short term hydrodynamic forces on the existing offshore facilities thus affecting ZADCO's structural integrity management plan. Therefore, it was important to quantify the extent of these changes on the existing jacket platforms such that appropriate modification to the current plan can be implemented. The present case study attempts to address the above issue by analyzing two representative jacket platforms, out of numerous platforms. SACS structural analysis software has been utilized for the analysis of these two platforms using hydrodynamic models developed for the two cases: (1) before the construction of artificial islands and (2) after the construction of ‘artificial islands’. Inplace, Fatigue and Pushover cases are part of major parameters used for the structural integrity of the offshore jacket platforms and the results of these analyses are part of critical input to the structural integrity management plans. It was observed that there were significant changes to the result of these analyses due to the introduction of artificial islands especially for the platforms which are having marginal reserve strength. This, in effect, alters current plan of inspection for critical nodes and members which need to be regularly inspected / monitored. It is also observed that the platforms pile on the mudline need to be inspected more frequently to know whether there are any changes to scouring of piles in soil. As a result of this case study it was established that such studies need to be performed while planning ‘artificial islands’ like facilities in offshore field like areas in order to asses its effect on existing facilities.
A Case Study of Modeling Workflow and Well Performance Assessment of a Complex Fluid / Tight Reservoir
Authors: Clara Cedric , Sherief Mohamed , Boalot Ahmed Tawfiq , El-Abd Salem Salem 
Published: November 2012

Abstract
Development of tight reservoirs with complex fluid behavior requires proper rock / fluid description and robust history match to understand and more accurately predict reservoir performance. This paper deals with reservoir modelling work undertaken for the evaluation of a tight reservoir, onshore Abu Dhabi.
The workflow for the construction of the static model with low permeabilities and strong heterogeneities is first discussed. The paper then presents a detailed analysis of reservoir surveillance data collected to assess the dynamic performance of a first well pair (producer / injector) drilled in the tight reservoir. Surveillance data include long term production / injection tests with multi PBU / PFO, interference testing and PLT data. A critical analysis of available data was performed in order to properly constrain the reservoir model. A PVT data review was also undertaken to build a robust Equation-of-State model.
A multi scenario history matching was performed with a compositional reservoir model and highlighted the importance of both permeability mapping and PVT modelling to match the complex dynamic well behavior. In particular, it was found that strong vertical compositional gradients prevail and can significantly impact well performance depending on structural elevation. This exercise showed the importance of analyzing data and understanding prevailing mechanisms driving well performance to properly constrain reservoir simulation model.
Because of limited available data at this stage of the development, significant uncertainties still exist. Hence the paper also presents key results from the uncertainty analysis and the data acquisition strategy designed to narrow identified uncertainties in order to optimize the development plan. Preliminary results from recent data acquisition campaign are also summarized.