bluuebunny/crossref_metadata_2025 huggingface dataset:
Leveraging Slim Hole Logging Tools in the Economic Development of the Ghawar Fields
Authors: Ariwodo I. , AL-Belowi A. R. , BinNasser R. H. , Kuchinski R. S. , Zainaddin I.
Published: February 2011

Traditionally, brown field developments have often required the plug-back and side-track of existing drain-holes, to target any nearby opportunities. With advances in drilling technology, there is a general preference to drill small diameter wells due to the comparative cost advantage of small holes.

In the recent times, this preference has led some wireline service companies to start to offer open-hole formation evaluation services with slim tools having diameter in the 2.0 -to- 2.5 in range. At present, most of the traditional petrophysical measurements can be acquired utilizing slim tools. In addition, several "specialized" measurements such as cross dipole sonic, formation pressure testing, and resistivity imaging can also be acquired. The use of battery and memory technologies has allowed these tools to be deployed using a broader range of conveyance techniques allowing for reduced risk in the entry of slim wells.

The provision of slim hole logging services has created an opportunity in the industry to leverage these tools for the economic development brown fields. Thus short horizontal sidetracks and well re-entry’s to test deeper horizons can be drilled and logged successfully. Saudi Aramco has been able to leverage these tools in its continued development of the giant Ghawar field. Some of the development projects are listed below; Some horizontal side-tracks with 3–7/8" hole sizes have been drilled under high dog-legs than was previously impossible and logged successfully.It is now possible to run well-completions in newly drilled wells that have well control problem. A provision is made to subsequently log these wells with slim wireline logging tools.It is now possible to run a complete suite of wireline logs across some old wells that were previously completed without a full formation evaluation logging suite.Slim-hole formation resistivity imaging services are now being provided, to aid in the identification of borehole break-out and fractures features that might affect the well’s productivity.Slim hole formation pressure testing have been acquired in slim wells in order to generate a pressure gradient, determine oil mobility, and define oil-water contacts

Several case studies would be used in this paper to demonstrate how Saudi Aramco has leveraged these slim wireline tools to realize some development opportunities. Also examples would be used to show that these slim tools do not compromise the quality of log data acquisition.
Natural Gas Hydrates: Development and Test of Innovative Methods for Gas Production From Hydrate-Bearing Sediments
Authors: Schicks J. M. , Spangenberg E. , Steinhauer B. , Klump J. , Giese R. , Erzinger J. , Haeckel M. , Bigalke N. , Savy J-P. , Kossel E. , Deusner C. , Wallmann K.
Published: February 2011

Huge amounts of CH4 bound in natural gas hydrates lead to the idea of using hydrate bearing sediments as an energy resource. Natural gas hydrates remain stable as long as they are in mechanical, thermal and chemical equilibrium with their environments. Thus, for the production of gas from hydrate bearing sediments, at least one of these equilibrium states must be disturbed by depressurization, thermal stimulation or addition of chemicals such as CO2. In the framework of the German national gas hydrate research project SUGAR (Submarine Gas Hydrate Reservoirs), all three reaction routes - alone or in combination - are tested. The aim is to find the most flexible and efficient, but also environmentally friendly method for gas production from hydrates. One method in this context is the thermal stimulation using in situ combustion. Therefore, a heat exchange reactor was designed and tested for the catalytic oxidation of methane. Furthermore, a large scale reservoir simulator (Volume 425 l) was realized, to synthesize hydrates in sediments under conditions similar to nature and to test the efficiency of the reactor. Thermocouples placed in the reservoir simulator collect data regarding the expansion of the heat front, respectively. These data are used for numerical simulations for up scaling from laboratory to field conditions. However, thermal stimulation may be used alone or in combination with CO2 sequestration. Therefore, laboratory studies on the methane production from pure hydrate phases as well as hydrate bearing sediments by use of CO2 injection are investigated using several analytic tools such as Nuclear Magnetic Resonance spectroscopy, confocal Raman spectroscopy and X-ray diffraction. In this study we present the experimental set up of the large scale reservoir simulator and the reactor design. Preliminary results show that the catalytic oxidation of CH4 in a countercurrent heat exchange reactor operated as a temperature controlled, autothermal reaction outside of the flammability limits of CH4 is a safe and promising tool for the thermal stimulation of hydrates. In addition, preliminary results from the laboratory studies on the CO2-CH4 swapping process in pure and porefilling gas hydrates are presented focussing on the kinetics of this process.
Ensuring Contractor Alignment With Safety Culture
Authors: van de Riet Ben PGM
Published: February 2011

The contractor ratio within the oil and gas extraction industry has increased significantly over the past two decades. With this rise in the number of contractors, the frequency of injury has also increased. Furthermore, compensation for contractor injuries is less regulated than for direct-hire employees, thus increasing liability and potential cost. As such, it has become imperative for oil and gas companies to better align and engage contactors to existing HSE policies, thereby decreasing the injury and accident frequency and preventing potential associated costs.

Confluent factors such as heightened globalization, the global recession and the integration of new technologies and extraction techniques have led to increased utilization of contractors in the oil and gas sector. While companies and contractors have the same objective as it pertains to safety – to prevent all injuries and accidents – it is ultimately the company that determines the level of safety in the workplace. To deliver improved safety outcomes for contractors, DuPont developed an approach to contractor safety management that has proven efficacious in decreasing the frequency of injuries and accidents among its contractors. The system is composed of six complementary processes: (1) the selection of contractors with satisfactory safety records, (2) the inclusion of safety standards in contractual obligations, (3) clarification of expectations upon award of bid, (4) orientation and training of contractor teams, (5) monitoring of safety activities, and (6) a post-contract evaluation to assess success and lessons learned.

To ensure efficacy, companies must first develop an appropriate context for contractor safety by familiarizing themselves with safety issues that affect contractors specifically, demonstrating a visible management commitment and developing a strong safety culture based on behavior modification and a collective responsibility for safety. While companies must manage contractor safety as they would their own personnel, the development of knowledge transfer methodologies, implementation strategies, and transparent monitoring processes are necessary to optimize safety outcomes for contractors. Furthermore, managers must integrate the six steps into their existing HSE policy and contractor recruitment process.

This paper will describe the benefits of improving the front-end contractor hiring process – selection of contractors with demonstrated satisfactory safety performance, contractual requirement to work safely and clarification of safety expectations upon award – as it not only initiates safety dialogue, but allows for an understanding of the financial and practical implications of incorporating expectations into their bid. Moreover, the paper will discuss the importance of instilling and reinforcing the company’s culture of safety. Companies that have implemented this management system have seen dramatic reductions in injuries and accidents among contractors, and consequently an increase in productivity and an improvement in employee morale.
Evaluation of Specialized Cement System for Long-Term Steam Injection Well Integrity
Authors: Pershikova E. M. , Chougnet-Sirapian A. , Loiseau A. , Khater W. , Garnier A.
Published: February 2011

Most heavy oil resources are found in shallow reservoirs. The challenging conditions of steam injection process to recover heavy oil from these wells impose additional requirements on zonal isolation material properties. At minimum, the ideal cement system must be designed with mechanical strength and flexibility sufficient to withstand the stresses induced by significant thermal loads. However, this ideal system has to acquire these properties at low placement temperatures and keep them at the minimum required level until abandonment and above. Conventional systems traditionally used for steam injection application don't satisfy these minimum properties requirements, which lead to various forms of leaks or even to complete steam breakthrough to the surface.

New specialized cement was developed to reliably maintain zonal isolation in shallow wells under steam injection conditions. This system, designed at the density range of 1,400-1,700 kg/cm3 (11.7–14.2 lbm/gal) is able to develop an excellent combination of mechanical strength and flexibility at the placement temperatures of 15-30 °C. Cement obtained after the initial low temperature curing was then aged at 350°C for 6 months. Every month, a temperature cycle (350°C to ambient temperature to 350°C) was simulated. Mechanical properties (compressive and tensile strengths and Young's modulus) were measured after 1, 3, and 9 months. Numerical simulations of sealant integrity performed with these properties in an annular geometry under shallow well conditions confirm long-term durability of the new system.

The cement's ability to withstand stresses encountered during steam injection was validated in a specific large-scale laboratory setup. A piece of cement sheath was subjected to two consequent temperature cycles from ~ 20 to 180°C with the a ramp-up of 0.6°C/min, equivalent to the worst case scenario for the proposed injector wells in the validation location. New cement system was capable of passing these conditions whereas conventional systems failed to maintain integrity of the well.

Thus, this study confirmed the capability of the new specialized cement system to ensure zonal isolation in shallow wells.
Assessment of CO2 Flooding Potential for Bakken Formation, Saskatchewan
Authors: Wang X. , Luo P. , Er V. , Huang S.
Published: February 2011

The Bakken is an extremely tight formation, with the oil contained mostly in siltstone and sandstone reservoirs with low porosity and permeability. In Saskatchewan alone, there could be an estimated 25 to 100 billion barrels of Bakken oil in place. At present, the combination of horizontal well drilling and the new multi-stage fracturing and completion technologies has been the key to economically unlocking the vast reserves of the Bakken formation. The primary recovery factor, however, remains rather low due to high capillary trapping. While waterflooding could result in unfavorable injectivity issues, carbon dioxide (CO2) miscible flooding provides a promising option for increasing the recovery factor. Higher oil recovery factor can be achieved with CO2 injection through multi-contact miscibility that results in vanishing interfacial tension, viscosity reduction, and oil swelling. This paper conducted a numerical simulation work as an effective and economical means of evaluating CO2 flooding potential for enhanced oil recovery. Different strategies were tested to compare the effects on oil recovery of injection well pattern, continuous and cyclic injection, waterflooding and CO2 flooding, injected gas composition, and heterogeneity. The simulation results show that CO2 flooding presents a technically promising method for recovering the vast Bakken oil.
Unconventional Imaging for Unconventional Reservoirs
Authors: Leskiw C. J. , Nowicki E. , Gates I. D.
Published: February 2011

Thermal stimulation of bitumen in oil sands reservoirs is a critical requirement for the success of steam-based recovery processes. If the bitumen is not heated, it remains at its original viscosity, often in the millions of centipoise, and thus is not mobilized so that it can be moved to a production well. All oil sands reservoirs are heterogeneous; both with respect to geology and fluid composition, and thus steam conformance of steam in the reservoir is not uniform. At present, realtime monitoring of the steam conformance zone in the reservoir is not possible and thus the spatial distribution of heat delivery to the reservoir is uncertain. In this research, a new method for detecting heterogeneity and monitoring steam chambers has been developed and tested by detailed thermal-acoustic reservoir simulation. Here, a thermal fluid flow simulator was coupled to a wave propagation simulator to evaluate the potential of identifying rock and fluid discontinuities within a reservoir by using coded white noise reflection processes. Digital communication systems employ coded white noise processes to advantageously make use of unexpected reflections from environmental heterogeneities. The proposed theory and subsequent simulations reveal that it is possible to resolve features of an unconventional recovery process as well as imaging of heterogeneity within the reservoir as it evolves by using white noise reflection methods. The properties of the signals described provide an opportunity for property detection at lower power levels and higher frequencies than traditional sceismic methods. Furthermore the signals are such that the noise from recovery processes and the native reservoir environment do not interfere with the detection methods allowing for the monitoring method to be used concurrently with the recovery process. A SAGD model is tested and the results show that white noise reflections can be used to detect the edge of steam chambers.
Quantitative Frac Pack Analysis Using Dual Tracer Logs and Down Hole Gauges
Authors: Sanford Jack , Bruton Jeff , Woomer Jim , Singh Amit , Flecker Mike
Published: February 2011

A combination of multiple down hole gauges and dual density / tracer logs were utilized to quantitatively evaluate distribution of fluid and proppant across a long perforated interval separated in two lobes and to quantify the annular pack percentage across the entire completion interval during a deepwater frac pack treatment in GoM. It was important to evaluate the achievement of an effective fracture in both lobes and define the annular pack percentage across the entire completion interval to be able to produce the well to its potential.

This technique quantitatively evaluated the entire frac pack process and determined screen out events in separate lobes and annular pack efficiency. The analysis also defined the dynamics of the treatment fluid and proppant slurry movement during the frac pack pumping operation and their final placement.

Several expected as well as unexpected conclusions and observations were identified. In summary, the diagnosis indicated that higher percentage of treatment fluid and proppant was received by the upper sandstone lobe. The exact proppant concentration at lower lobe screen out was identified. A baseline pre-pack value was established, which allowed the annular pack percentage to be calculated across the entire interval. It also provided detailed information on the sequence of events during washout at the crossover tool. All of these allowed the operator to confidently maximize deliverability from the subject well, which is currently producing 110 MMcfd.

The results from this case history and the technique described should result in a step change in frac pack evaluation. Quantitative evaluation eliminates any doubts about the effectiveness of the annular pack and allows operators to produce their assets at maximum deliverability. Additionally, it assists future completion designs and type selection.
Geochemical and Geological Characterisation of the Duvernay and Muskwa Formations in Alberta
Authors: Rokosh C. D. , Anderson S. D. , Beaton A. P. , Berhane M. , Pawlowicz J.
Published: February 2011

The ERCB/AGS has collected over 270 core samples from the Duvernay and Muskwa formations in Alberta and run a series of tests to characterize the formation for resource assessment. The geochemical and geological tests include adsorption isotherm, Rock-Eval/TOC, XRD whole rock and clay mineralogy, permeameter, porosimetry, thin section analysis and SEM imaging. The purpose of this talk is to discuss the regional geological and geochemical attributes of the Duvernay and to a lesser extent the Muskwa leading to a shale gas resource assessment. An important aspect of our study is that the samples wer taken to represent a variety of lithofacies and colour variations, for example, and do not necessarily represent the best reservoi rocks. Our purpose is to reveal the attributes of rocks that have resource potential, or lack thereof, as opposed to identifying rocks with reservoir potential. The data will be presented using a series of maps and sections to show the spatial and temporal variations.
Experimental Investigation of Vapor Extraction Process for the Recovery of Bitumen From Vuggy Porous Media
Authors: Rezaei N. , Mohammadzadeh O. , Chatzis I.
Published: February 2011

The application of VAPEX process was carried out in sintered homogeneous and vuggy porosity media with different matrix permeability and porosity, to investigate the behavior of vapor extraction process in vuggy media as a potential recovery process. The VAPEX experiments were conducted using Cold Lake bitumen, and n-pentane as the hydrocarbon solvent. Seven different models were made, four of which were vugular media with different vuggy-to-total pore volume ratios. The vugs were arranged in aligned and staggered configurations. Three homogeneous sintered glass beads models of different permeability and porosity were also made. The vugs in sintered models were created by embedding wood particles of uniform volume (20 mm3 each) in the glass beads continuum between two parallel glass plates and by heating them in the muffle furnace. During the VAPEX experiments, analysis of the live and dead oil production rates, solvent content, and residual oil were conducted. It was observed that the vugs could appreciably facilitate the production of bitumen from the vuggy models compared to the homogeneous model with the same matrix glass bead size. The increase in the vug porosity of the porous space significantly increased the live and dead oil production rates of bitumen and slightly decreased the extent of residual oil saturation left in the model. Unlike the sintered homogeneous models in which the production rate of bitumen remains more or less constant during the VAPEX process, the vuggy porosity models display a boost in the rate of oil production when several vugs are being invaded by the solvent vapor. This behavior was more pronounced in the case of aligned vugs were the vugs were closer to each other and more vugs were invaded simultaneously compared to the staggered vug configuration. The enhanced pore-level mixing of solvent with bitumen, improved petrophysical properties of the porous medium, and the flow communication of matrix with the vugs were found to be important in draining the live oil towards the production well at higher rates.
Correlation Of Outcrop, Seismic, Core Plugs And Thin Sections In Cretaceous Carbonate Rocks From Wasia Group In The U.A.E
Authors: El Husseiny A. H. , Vega S. , Al Mesaabi S. , Ali M. , Weger R. , Eberli G.
Published: February 2011

Previous study, of a geological and petrophysical investigation from an outcrop in the UAE, found a potential correlation between acoustic velocities and fracture density. However, it was not clear what could be the effect of this correlation in the seismic response. The aim of this paper is to extend this previous study to better understand its results and to investigate their significance in the seismic response. To achieve this purpose, we correlated geological and geophysical parameters at four different scales: outcrop, seismic, core plugs and thin sections. We acquired a seismic line on the top of an outcrop. From the same outcrop we examined 17 core plugs and 30 thin sections along different locations. We found that acoustic velocities, measured in the lab, decrease with increase in fracture density. This result was supported by the outcomes of the outcrop-seismic correlation where changes in fracture density were found to be an important factor that affects the seismic response in carbonate rocks. Such correlation can lead to better understanding of the seismic response which can result in an improvement in seismic interpretation of areas with similar geological conditions.
Unconventional Oil Exploration Potential in Early Mature Source Rock Kitchens
Authors: Taher Ahmed K.
Published: February 2011

Most of the simple anticlinal structural traps have already been discovered in Abu Dhabi and most other places in the world. New exploration activities need to be concentrated on other, less obvious plays and subtler trap styles. Oil exploration directly from early mature source rock kitchen is an example of such an unconventional new play type.

Mature source rock strata are normally characterized by strong oil shows while drilling and high hydrocarbon saturations in the interpreted logs. In the past, several attempts have been made in Abu Dhabi to test these promising zones but the productivity was either nil or very low. The low productivity values are mainly related to the low permeability of source rock sediments. Also, the low productivity could be attributed to the conventional testing used for these tight reservoirs.

Oil exploration from the source rock kitchens need to be focused on the areas that are characterized by rich organic matter content and it’s in the early stages of oil generation. Finding economically attractive oil accumulations in the source rock kitchen is linearly increases with the increase of porosity values.

The development of source rock porosity could be attributed to the organic matter richness and the argillaceous nature of these source rock intervals. Also, the conversion of solid organic particles into liquid components will provide additional space for generated hydrocarbons.

The maturation modeling of the Cenomanian, Shilaif Formation indicated the presence of early mature kitchens in the offshore and southern onshore synclines. In some of these localized kitchens, significant quantities of oil were generated but not expelled into the surrounding structures especially in the southwestern onshore syncline. Similarly, the Oxfordian Diyab (Hanifa) Formation is prospective mainly in the northern offshore area. In this area, the Diyab source rock did not reach the expulsion phase yet and the wells data of this area indicated the presence of potential oil accumulations in this area.

The lateral seals for the localized source rock reservoirs are provided by the solid kerogen of the immature source rock at the basin margins. The top seal is provided by thick and tight sediments of Tuwayil and this will delay the primary migration of hydrocarbon out of these kitchens and make it more attractive for exploration activities.
Downhole and Topside Scale Challenge "Removal, Prevention and Inhibition Strategy"
Authors: Al Salami Aisha R. , Monem Alaa A.
Published: February 2011

Downhole scale deposition in the producing strings and wellbores is becoming a serious problem for many oil operating companies, especially when dealing with horizontal wells. For those companies that are using water flood to maintain the reservoir pressure, the problem will be greater as the scale is often calcium, barium and strontium sulphate besides the topside scaling phenomena and the disadvantages of solids at surface facilities

The options for scale removal vary from chemical treatment or mechanical removals and at the worst conditions full rig work over to replace the production tubing.

Consequently, the oil field scale treatment philosophy is "scale prevention is better than cure", accordingly, implementing successful inhibition program is generally the most efficient scale treatment strategy.

This inhibition strategy is based on many factors to enable an appropriate assessment and reliable conclusions particularly for carbonate reservoirs: How the inhibitor interacts with the formation rock matrix.Thermal stability of the inhibitor.Deployment and return profile

In this paper, a severe downhole scale problem is presented focusing on all the treatment parameters starting from the traditional chemical & mechanical removal techniques and ending by the squeeze inhibition programs utilizing the neutralized phosphonate chemistry selected to extend the inhibitor life time, the paper will cover: Impact of the naturalized phosphonate on carbonate reservoirInhibition programs and their modification to improve and extend the squeeze life time without damaging the reservoir materialInhibitor deployment, fluid returns monitoring and optimization.Impact of the water breakthrough & brines mixing on scale formation at surface facilitiesNegative impact of solids formation on the topside facilitiesScale dissolver chemical selection and optimization
Hydrogen Integration For Petroleum & Power Industries
Authors: Naim Mohammed , Muharrami Fawaz Al , Lamki Bader Al
Published: February 2011

With the increasing global awareness for the preservation of the environment, Governments became convinced that our industrial practices had an impact towards environmental deterioration through an anthropogenic climate change, which mandated Governments to demonstrate actions towards serious cutting back of carbon emissions.

It is accepted that the Petroleum and Power industries are among the highest sources of Carbon Dioxide (CO2) emissions and whilst they have an impressive record of constantly searching for ways to meet the energy supply with cleaner and more efficient technologies; they continue to be challenged to meet the energy demand under increasing local and global regulations to reduce their Carbon footprint forcing them to consider alternative approaches for facilities design and operation.

Apart from proceeding challenge; these two industries have something else in common namely: their need for Hydrogen generation. Hydrogen demand is evidently increasing in Petroleum industries for various uses in Refineries, Petrochemicals and Fertilizer industries. Similarly; demand for Hydrogen as clean source of energy is growing in the Power industry. It is this common need for Hydrogen that directed our attention to identify an opportunity for cross industrial integration through Hydrogen production resulting in various substantial environmental & business benefits in an affordable and reliable way.
Pilot of Gas-Lift System as Building Block in the Development Strategy for a Super Giant Field
Authors: Yaslam Maged Mabrook , Fahim Mohamed , Abdallah Dalia , Helmy Hamdy , Mansoori Yousof Al
Published: February 2011

A super Giant field production sustainability is essential and has to be sustained for longer period of time, therefore different techniques have been introduced and tested to overcome the various reservoir issues. Gas Lift technique (GL) has been considered as one of the effective mitigation actions to reactive the dead wells, enhance recovery factor (RF) and accelerate the production from both technical and economical points of view. Prior the full field implementation, it was decided to select a GL Pilot for testing and data gathering, the planned GL Pilot consists of 10 wells which have been selected from various reservoir units and completions to analyze the differences in the performance. The selected Pilot wells were inactive prior to GL implementation (with no oil production) as per set strategy which calls for using of the GL system to reactive the dead wells only. The Pilot started production in November 2008 with almost a total oil production rate of 14 Mstb/d using GL system and the current average rates of the pilot (as of Jan. 2010) are as follow; average oil rate~ 13,000 bbl/d, average water rate of~ 19,000 bblw/d, average gross rate of 32,000 bbl/d and average W.C%~ 60%. The pilot performance was achieved with total gas lift injection~ 6 MMSCFD (which means 0.6 MMSCFD per well in average). The total oil recovered from the current GL pilot, during a period of one year (330 producing days) is 4.15 MM bbl, this can be roughly turned in to cash amount equal to $ 207.5 MM (assuming 50$/bbl).

These resulted values from the GL wells have been surging up and down as a result of the optimization process in order to minimize the W.C% and increase the oil rate. Real Time Optimization (RTO) process is important and currently is ongoing (last stage) to be fully implemented to optimize especially the GL produced water (amount and treatment) in addition to the oil production. Gas quality, availability and conditions have been ensured with the current available field facilities.

Pilot Modeling is vital to assess each well behavior, therefore every well has been modeled using Inflow/Outflow Software and pertaining data has been continuously validated and updated according to the production tests and actual findings. Different monitoring tools have been used such as RST, PLT and Gas Lift surveys to identify the actual well performance. The Pilot modeling results have been used as a guidance to predict the full field future GL performance.

Generally, the Pilot results revealed the important questions and achieved the core objectives related the GL system for full field implementation.
Application of Digital Core Description Methods in a Reservoir Characterisation Study: A Review of Traditional Versus Potential Future Method
Authors: Al-Suwaidi M. , Williams M. , Ottinger G.
Published: February 2011

Core description is a fundamental step in the reservoir characterization process. Quality core descriptions are not only important for depositional and diagenetic understandings, but also critical to the development of sequence stratigraphic frameworks. This can have significant effects on development strategies for a reservoir through their impact on geological and simulation models.

There are increasing pressures to integrate large volumes of data rapidly and efficiently into geological models, especially in development and production settings. Traditional methods of core description using pen and paper are generally slow to produce the quality-controlled digital data required for geologic models. Digital core description has long been seen as a potential tool to speed up the integration of core data. However digital description tools have often been found to be cumbersome and slow, leading to questions about the practicality of the process and the reluctance of many describers to use the tool.

In a recent effort to describe a large amount of core as part of a large carbonate reservoir characterization study, initial efforts were carried out using traditional methods while later phases of the study used direct digital description. Due to the extensive footage of core that was to be described a large group of describers, with varied backgrounds and experience levels, were tasked to complete the work in a timely manner. The study was divided into two phases. In the first phase descriptions were carried out in a traditional manner with pen and paper and later digitized, while in the second phase a major effort was undertaken to introduce direct digital description. It was therefore of key importance to establish systems that would guide the describers in the information that they collected and to ensure consistency in the descriptions. Using a digital data entry system helped ensure consistency in description as well as integration of other data such as log and porosity/permeability data into a convenient format that could be viewed by the describer. While traditional methods were found to be much faster initially the resulting product was only available for analysis after digitization had been carried out in the office, in some cases months later, and was only usable after quality control editing, which was often not carried out by the describers themselves. Due to varying styles of description different characteristics of the core were emphasized by different describers and often described differently, creating challenges later when the data was analyzed.

In this paper we will discuss the advantages and disadvantages of traditional methods compared to our attempts at direct digital core description. Here we will show that the
Determination of Critical In-situ Stress Parameters for Future Well Placement: An Integrated Case Study From C-Series Fields of Tapti-Daman Block, Mumbai Offshore, India
Authors: Parashar Sarvagya , Sikdar Koushik , Roy Dipanka B , Shrivastva Chandramani , Kumbhar V. B. , Majithia P. P. , Baishya R. C. , Avtar Ram
Published: February 2011

Tapti-Daman is one of the major hydrocarbon-producing clastic sub basins situated in the northeast region of the Mumbai High structure in Western offshore India. Tapti-Daman sub-basin hosts more than 6 Km of clastic dominated sediments ranging from late Paleocene to Recent, underlained by basement rocks.

Drilling failure has been reported in few wells in Tapti-Daman block in the past, which subsequently resulted in well collapse and abandoning the drilled section. The limitation of stress computation in the deviated and horizontal wells further introduced complexity in overcoming the wellbore stability issue. To address this, an innovative methodology was developed to assess the stress regime in this field. An accurate estimation of the stress parameters in the backdrop of geological information led to a more accurate and reliable geomechanical model.

Using a multiwell dataset from the C-Structure in the Tapti-Daman block, stress azimuth from vertical and deviated wells was determined with an advanced interpretation module. The module utilizes the borehole microresistivity image-derived azimuths of drilling failure signatures (i.e. breakouts, induced fractures, etc.) to decipher the shape of the stress tensor (Q-factor) and azimuth of minimum horizontal stress. The detailed analysis of the Q-factor and Sh leads to determining stress regime and anisotropy (as a function of well trajectory).

The analysis revealed that the present day in situ stress in the study area is compressional in nature, where S3 is vertical (sH>sh>sV) and the minimum horizontal stress azimuth is towards NE-SW. This critical information is represented in 2D stereographic stress plots considering the Sv/Sh or Smax/Smin ratios to ascertain the safe window for various wellbore stability parameters such as sanding, breakout, mudloss, tensional fractures, anisotropy and probability of fracture opening with respect to insitu stresses.

The inferences derived provide an edge in optimizing the well trajectories to avoid wellbore stability issues.
Well Integrity Management System WIMS Development
Authors: Daghmouni Hamdi , El Manci Magdy , Abdel rady Sayed Aly , Shattawa Yousef
Published: February 2011

Operator’s continuing success depends on the ability to manage its reservoirs and to exploit them in the most efficient manner to sustain production targets, while maintaining a high level of safety performance. Ensuring the integrity of wells is essential to achieve these requirements. Some of operated wells are reaching an age where an increasing frequency of integrity issues is becoming a concern. In addition, new wells may face greater threats to their integrity, for example due to the more corrosive reservoir fluids often encountered in existing and new developments. Wells operating under high annulus pressure are at risk of loss of pressure containment either in the form of releasing formation fluids to atmosphere or cross flow and charging up shallow reservoirs or aquifers. When monitoring trends of annulus pressures it should be taken into account that even with relatively low sustainable pressure there is a possibility that cross flow to shallow reservoirs could be taking place. This is especially true for C-C annulus "B" of most oil and water injection wells where shallow water reservoirs are straddled by one casing. Any sustainable annulus pressure on this annulus is undesirable and is to be critically reviewed.

A well may also show annuli pressure due to thermal effect and this must always be checked for when a new well is being produced for the first time or when a well is brought into production after being shut in for a long period. It should be remembered that pressure increase due to thermal effect could be considerable.

One of the most key integrity challenges is the Sustained Annuli Pressure in A, B and C casings.

The asset–specific Well Integrity Management System must ensure that there is adequate isolation between the formations fluids (hydrocarbon-bearing reservoirs) and the surface environment at all times during well life. Responsibility for the well and its integrity is transferred between different parts of the organization during these activities, and this must be reflected in the integrity management system.

The development and implementation of Well Integrity Management System (WIMS) will assist effective management of wells and hence to contribute to the achievement of its business objectives.

The Well Integrity Management System (WIMS) shall provide direction regarding the manner in which wells are to be designed, constructed, operated, work-over up to abandonment. This is to assure the integrity during the well life cycle through monitoring, preventive, corrective practices and assurance system, which would reduce frequent work-over, operating down time, extend life cycle for wells, and secure asset integrity & safety and environment.
Inline Water Separation IWS Field Prototype Development and Testing
Authors: Xiao J. J. , White Ramsey , Aramco Saudi , Wang Shoubo , Gomez Luis
Published: February 2011

A compact multiphase Inline Water Separation (IWS) field prototype system has been developed and trial tested. The system consists of a Gas-Liquid Cylindrical Cyclone (GLCC), a Liquid-Liquid Pipe Separator (LLPS), a Liquid-Liquid Cylindrical Cyclone (LLCC) and a two-stage Liquid-Liquid Hydrocyclones (LLHC). The function of the system is to separate a significant portion of the produced water from a production stream while the remaining production fluids of gas, oil and reduced water are still sent to existing processing facilities. The quality of the separated water meets the requirement for water injection or direct disposal. The compact IWS can be installed either at the wellhead or downstream of a production manifold to handle multiple wells on land, offshore platform. The benefit of such a system includes increasing field water handling capacity, reducing the size and cost of the downstream separation facility, and reviving dead low-pressure wells.

The field prototype has been susccefully tested in the field. The overall water separation efficiency, defined as the percentage of water removed from the total water production, averages at 70%. The outlet water quality is less than 35 ppm oil concentration. The results of the tests show that it is feasible to integrate GLCC, LLCC, LLPS and LLHC into a compact multiphase separation system for bulk produced water removal from a production stream.
Crossing Barriers In Language And Comprehension To Improve Worker Safety
Authors: Campbell Hugh , Duguay Alexandra , Lecoindre Christelle
Published: February 2011

Transferring information that is critical to safe work is very difficult in culturally diverse work sites. Language and reading comprehension differs greatly from person to person, with increasing complexity when sharing information outside of the native language of the receiver. The challenge - to simplify the message while not diluting the salient points. The opportunity - creation of a short form material safety data sheet using pictograms and graphics rather than high amounts of text. The benefit - Higher degree of worker understanding and confidence resulting in lower incidents of near miss and injury on-site.

Total Abu Al Bukhoosh (TABK) has launched a new short-form Material Safety Data Sheet (SMSDS) system that addresses pre-existing boundaries to effective communication of chemical hazards and risks. The pictorial form overcomes limitations of reading comprehension and language to ensure the highest degree of health and safety for our workers.

The SMSDS is a single page, easy to read document that contains key information regarding the potential health effects, hazards and response measures of any particular chemical. The SMSDS was created by TABK in order to summarize the standard Material Safety Data Sheets while maintaining compliance with regulatory requirements. All with the aim of improving the usability of information made available to the end user of the chemical.

In addition to the safety precautions that should be taken when working with the chemicals (e.g. wearing gloves, goggles or a masks etc.) another important issue that the SMSDS addresses is the correct response protocols that should be taken when a problem occurs, whether it is a spill, an accident or a fire.

While kept within easy access of the work site, the information is also available online. The intranet database provides efficient management of information regarding the potentially hazardous materials in use at TABK, and offers a simple means to re-print sheets for convenience.
Optimal Strategies to Enhance Oil Recovery in Under-Saturated Carbonate Reservoirs: A Case Study
Authors: Jamshidnezhad M. , Ghazvinian T.
Published: February 2011

Gas injection seems to be an important method for increasing recovery in declining oil reservoirs. The method can be applied especially in the reservoirs with oil-wet rocks. Although sweep efficiency of injected gas is poor due to high gas mobility, in most cases gas is injected together with or alternating with water to increase its sweep efficiency. Gas injection into under-saturated carbonate reservoirs is still challenging. This paper studies different strategies to find the optimum method to recover more oil from a huge under-saturated carbonate reservoir. The reservoir locates in the Southern part of Iran and remains under-saturated for all its life. Giant gas resources in the area and the wettability characteristic dictate gas injection. In this paper, we build the reservoir model and simulate three different strategies: natural depletion, immiscible natural gas injection, and miscible enriched gas injection. In case of miscible gas injection, enrichment is done so that the minimum miscibility pressure (MMP) is set equal to initial reservoir pressure. Simulations are conducted with two commercial simulators to investigate the effects of different reservoir simulators. Detailed of simulation and results are elucidated in the paper.
Environmental Assessment of CO2 Storage Site: Specific Monitoring Program and Study Needed to Assess Environmental Impacts
Authors: Quisel N. , Rampnoux N. , Thomas S.
Published: February 2011

Ensuring societal acceptance of Carbon Capture and Storage (CCS) projects is strongly linked to the environmental impact assessment of projects. CCS implementation should not only be considered a technical solution to the carbon emissions issue as societal issues play at least an equal role in the full acceptance of the technology. CCS projects should be designed to minimize environmental impacts to the highest degree possible and prove that the environmental issues can be monitored during development and operational phases.

As a consequence, CCS projects must integrate appropriate monitoring programs and develop environmental studies in order to gather and analyse required information and to communicate with stakeholders.

This paper proposes to prioritize processes and techniques that can be implemented to monitor environmental impacts of CO2 storage sites. The first part of the paper focuses on the key monitoring techniques and assesses monitoring programs that can be used to gather required information.

The second part of the paper presents the importance of the additional studies needed to assess environmental, health, and safety impacts in the event of a leak from the storage site that should be recommended as part of the environmental methodology. This study can be viewed as the starting point for the decision analysis related to CCS projects and provides some guidance in establishing a specific monitoring program and an environmental assessment plan. It could be considered as an important step in the identification of the development options and optimization of the investment strategy that is required at the front end of any large and complicated project.
Making Real-Time Fluid Decisions with Real-Time Fluid Data at the Rig Site
Authors: Broussard S. , Gonzalez P. , Murphy R. , Marvel C.
Published: February 2011

Critical decision making is a common occurrence in oilfield production, and operators depend on accurate drilling-fluid data to determine the appropriate course of action for the success of their drilling program. Many critical downhole decisions made by operators are based on drilling-fluid data that could be up to 24 hours old and do not accurately reflect the current fluid conditions in the wellbore. During these potentially hazardous situations, the rig site drilling-fluids representative must contend with drilling fluid issues and may not have the time to conduct repeated, consecutive, and consistent tests on the fluid to offer accurate recommendations to the operator. Decisions may be impacted or delayed by using fluid properties measured before or after issues are identified, and problems may escalate. Automating routine fluid-property tests provides access to more precise and dependable drilling-fluid properties in real time, which, in turn, can lead to real-time data that becomes vital when crucial decisions must be made.

A major oilfield service company recently conducted field trials of its automated drilling-fluids measurement equipment in South Texas. Automated measurements of density and rheological properties were conducted on water-based and oil-based drilling fluids. Traditional measurement routines were also conducted throughout the field trials for the purpose of comparative analysis with the automated equipment. Automated and traditional measurement recordings were compiled at the rig site, and data were exchanged to the service company’s laboratory facility for analysis. Data exchanges were accomplished via the service company’s proprietary software, which can be used for analysis, data transmission, and data display.

This paper discusses the results of these field trials and focuses on the comparative analysis of the automated measurements and traditional measurements, strengths and limitations of the instruments, the integration of the instrument package into the routine functions of a drilling rig, the service company’s capabilities of presenting the real-time data, and the overall lessons learned during the course of the field trials.