bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rock Mechanics Lab Testing and Computerized Simulation of Bit Dynamics Improves Drilling Performance in Horizontal Chalk Reservoirs
Authors: Gillick S. , Hamilton R. , Singh A. , Kraan A. van der Pouw 
Published: January 2008

Abstract
Maersk Oil and Gas AS are typically drilling the carbonate reservoirs in the Danish Sector of the North Sea in 8½" horizontal hole sections, with section lengths regularly over 15,000 ft. The two lithological components of the formation show a large variation in geo-mechanical properties: a soft, plastic chalk matrix and large, hard, brittle, chert nodules. Impact loading on cutting structures and penetration difficulties in the hard, microcrystalline chert are generally the limiting factors on bit longevity and performance. These long horizontal sections highlighted the opportunity for optimising the durability of single bit runs. In June 2001 Maersk Oil implemented a bit development priority that was to produce significant, beneficial results.
Optimization of Big-Bore HTHP Wells to Exploit a Low Pressure Reservoir in Indonesia
Authors: Benesch J. M. , Nor Nazri 
Published: January 2008

Abstract
A Big-Bore HTHP drilling and completion program of seven wells was undertaken under challenging conditions in a low pressure carbonate reef in Indonesia. Significant enhancements made during the program substantially reduced well times and cost. These wells incorporated the largest tubingless gas completions in the world. Higher than anticipated initial flow rates were achieved through an innovative strategy to decrease formation damage. The wells were completed open-hole without pumping kill weight fluids at the end of underbalanced drilling operations. These wells are the first to combine Big-Bore completions, drill-in liners and underbalanced drilling in individual wellbores.
3D Geological Model to Reservoir Simulation of the Lower Arab Formation – Abu Al Bukhoosh (ABK) Field, Offshore Abu Dhabi
Authors: Javaux C. , Cochet F. , Gauthier B. , Prinet C. , Ten haven L. , Herriou M. 
Published: January 2008

Summary
The Abu Al Bukhoosh (ABK) field is already in production since 1974. At this stage, the distribution of the remaining reserves and further development programme, including gas injection, become highly sensitive to a better understanding of the reservoir. The present paper focuses on the detailed 3D geological model of the ABK Lower Arab Formation conducted through an integrated study. In particular, it incorporates an original methodology to determine rock types from cores and extend them to wireline logs, build a sequence stratigraphy-related reservoir layering, populate the 3D model for rock types and introduce the effects of fracturing. Emphasis is also placed upon the input of the 3D geological model in the reservoir simulation model.
Utilizing Perforation Performance Module (PPM) and Extreme Under-Balance (EUB) Perforating to Maximize Asset Value in Deep Low Porosity - Low Permeability Gas Reservoirs – A case study from VICO Indonesia
Authors: Irvana Sonny , Sumaryanto Sumaryanto , Hari Kontha I Nyoman , Joenoes Krisjahbana , Nieuwland Bastiaan , Kaura Jiten D 
Published: January 2008

Proposal
VICO Indonesia is an Oil and Gas Company operating the Sanga-Sanga PSC in East Kalimantan. This PSC comprises of four operating assets: Nilam, Mutiara, Semberah and Badak. The depositional environment consists of fluvial-deltaic sands with oil and gas bearing sandstone formations stacked on top of each other, there are on average ten to twenty zones per well. Exploiting these reservoirs to their maximum potential to meet the gas delivery to Bontang LNG plant is the object of the asset teams. Maximizing asset value by increasing production with lower investment is very important within the VICO organization.
In order to achieve the above objective at optimal costs, a lot of emphasis is being given to rigless activities. The main activity is to open these stacked gas bearing sandstone formations by adding perforations either by wireline or by utilizing extreme under balanced perforating techniques.
This paper focuses on the utilization of state-of-the-art software, perforation performance module (PPM) in conjunction with extreme under balanced (EUB) perforating technique for maximizing gas production from the deep low permeability and low porosity gas bearing reservoirs. This paper presents various cases showing how effectively and economically these deep sandstone formations can be completed to maximize the return on investment (ROI). The PPM was utilized to predict the performance from these reservoirs. The actual post-job results were then used to verify the predictions. This was essentially to assist VICO in making the decisions in line with the economic benefits for various perforating techniques.
Interactive Visualization of Uncertainty in Well Test Interpretation
Authors: Khasanov Mars , Khabibullin Rinat , Krasnov Vitaly 
Published: January 2008

Proposal
A way to represent the uncertainty in well test interpretation software isproposed. An uncertainty guided, interactive method of model parametersidentification is introduced. Examples of method application are given.
Well test interpretation problem is usually posed as model parametersidentification based on the criterion of matching synthetic and actual pressuretransient response. It is an ill-posed inverse problem. It means that thesolution of this problem is very sensitive to the errors in input data and evenfor the small variations of input data there can exist the large set ofallowable solutions.
Though the problem of uncertainty is discussed in literature, most ofcommercial software for well test interpretation automatically offers only thesingle result that yields the best match of the model and actual data. Thissingle outcome is often mistaken for reality. Also sometimes engineer hasadditional information, which indicates that other value of parameter is moreprobable than what is automatically identified. But using the standard welltest interpretation software it's pretty difficult to realize how close is thisvalue to the allowable set of values.
So when creating software for well test interpretation it is important toprovide the engineer with the means to vary values of model parameters withinteractive feedback about how good this value fits the data.
In presenting work the new approach to visualization of uncertainty in welltest interpretation is proposed. The approach is based on mapping of theresidual between the synthetic and actual pressure response as a function ofidentified values.
Residual maps guide the interpreter when making decision about values ofmodel parameters and allow having a more direct sense of exploring the space ofuncertainty. The interactivity is added by enabling the engineer to visuallypick up the solution, which he thinks is the most appropriate for theparticular case. Interactive visualization improves decision-making byconfronting engineer with the clear representation of uncertainty.
Enhanced Reliability with Unique Tubing-Retrievable Safety Valve Design
Authors: Vinzant Mike , Vick James , Parakka Anthony 
Published: January 2008

Abstract
Tubing-retrievable safety valve (TRSV) performance has been improveddrastically over the last decade as a result of simplified design concepts,increased use of non-elastomeric and metal-to-metal (M-t-M) sealing materials,and enhanced validation testing. At the same time, the demands imposed bydeep-water, high-pressure/high-temperature (HPHT) environments, high-flow-rategas reservoirs and remote subsea applications have also increased, and in spiteof continuing improvement in safety-valve technology, equipment has continuedto be pushed to its limits. As a result, higher valve-opening pressuresassociated with deep-set applications have emerged, and to address these needs,conventional solutions have focused on balancing the wellbore and its reactionto the hydraulic piston area using mechanisms that require additional sealsand/or gas-charged chambers. These solutions are heavily dependent onelastomeric seals and/or the permanent, long-term containment of a dome (gas)charge or pressure counterbalance, to maintain reliability. Unfortunately,dynamic elastomeric seals have posed a major limitation when design intentfocuses on equipment that will provide enhanced life-of-the-wellreliability.
This paper will review a unique TRSV design that is a revolutionary newconcept. This design incorporates a floating magnetic coupler that allows thehydraulic actuator to be positioned in a dedicated chamber isolated fromcontact with well fluids and pressure. Since the hydraulic actuator has beenseparated from the tubing wellbore, this new valve is the first in the industryto have 100% M-t-M sealing with no moving seals within the tubing wellbore.
The new intrinsically simple design: Increases environmental and personnel safetyReduces system costsReduces sealing requirementsProvides an extremely reliable tubing retrievable safety valveEnhances life-of-the-well.
Disproportionate Permeability Reduction by Soft Preformed Microgels
Authors: Chauveteau Guy , Tabary René , Blin Nicolas , Renard Michel , Rousseau David , Faber Rien 
Published: January 2008

AbstractInjecting soft, stable and size-controlled microgels to reduce water production is a new concept, introduced some years ago, we refer to as STARPOL process. Microgels specifically designed for water shutoff (WSO) treatments do not contain toxic products and can be produced to be fully self-repulsive. They adsorb onto rock pore surface by forming soft monolayers with a thickness equal to their size. This size can be adjusted as desired during the manufacturing process. As a consequence, water permeability can be reduced as desired. Microgel chemistry is chosen to be insensitive to pH and salinity variations.This paper reports laboratory results obtained with a new type of microgel expected to be available at industrial scale in a near future, under both powder and liquid form. The results include their characteristics in solution (size, intrinsic viscosity, mutual interactions and rheology), as well as their performances in porous media (model granular packs and Berea sandstones). These microgels were found to reduce water permeability strongly by forming thick adsorbed layers which are so soft that oil permeability is not affected. As expected from their crosslinked structure, their mechanical and thermal stability is excellent: shear rates as high as 1.5×104 s−1 or one month aging at 150°C do not reduce their viscosity. Another very significant advantage of microgels over gelling systems is that they can be quasi-ideally placed without need of zonal isolation when properly designed according to reservoir conditions: in this case, they penetrate almost exclusively into the highest permeability layers.
Small outer Diameter, Big Bore Permanent Straddle System
Authors: Halvorsen Helge , Enerstvedt Eirik 
Published: January 2008

Abstract
This paper describes a case history of a "Small Outer Diameter -Big Bore Permanent Straddle System" installed in a well offshore in the North Sea December 2002.
The purpose of the platform well as an injector was WAG injection in the lower zones. To obtain this, the upper zones had to be isolated due to corrosion in the tubing. This was successfully achieved with Weatherford Seal Bore Packer system, leaving access to the lower zones with 2 3/8″ CT through the Straddle.
Economically it is cheaper to use a solution like this instead of changing the whole tubing with a full workover of the well.
The Keys to Successfully Acidizing Horizontal Injection Wells in the Marlim Sul Field
Authors: Da Silva Mario Germino Ferreira , Calderon Agostinho , Motta Eduardo Ponce da 
Published: January 2008

Abstract
This paper presents field data from the acidizing of several horizontal, gravel-packed, water injection wells in the deepwater field of Marlim Sul, Campos Basin, Brazil. We describe the keys to the strategy that led us to achieve highly successful results, which involved changes in the composition of the drill-in fluids (DIF), the use controlled acidizing parameters and special acidizing tools that provide mechanical diversion, and modifications in the conventional acidizing program, that made fluids compatible with the acidizing tools. Since the main type of damage present in the wells is the mudcake from the DIF, small acid volumes are able to remove all damage. The small damage penetration also recommends low injection rates, instead of the traditional high rates that would not provide enough contact time to dissolve the damage and would create preferential paths for the acid.
Before the use of the new strategy, the injections wells in Marlim Sul were treated with regular wash pipes, with no guarantee of mechanical diversion, and poor results. After starting to use specially designed acidizing tools (one-trip or straddle packer), and to minimize solids and filtrate in the DIF, the average completion efficiency (CE) after the treatments became 77%, what delivered injectivity indexes far above the injection quotas defined by reservoir engineering. A subsequent improvement was to start acidizing the whole horizontal section, instead of only the points of higher damage, as shown by the flowmeter logs. This has made the final completion efficiencies come very close to 100% for all treatments. As a consequence of that, and of the good results also obtained in the producer wells, the production platform P-40 became overloaded with oil and a new production facility, FPSO-Marlim Sul, had to be added to the project to accommodate the extra oil. Due to the good results obtained, all the other deepwater fields at the Campos basin adopted the same strategy for acidizing their horizontal injectors.
The outline of the strategy presented in this paper may be helpful for improving the results of acidizing jobs of horizontal water injectors in similar offshore fields around the world. The pioneer application of special acidizing tools, the modifications in the DIF composition, and the use of controlled acidizing parameters constitute very important advances for the complex task of acidizing horizontal wells.
Optimization of Rotary Steerable System Bottomhole Assemblies Minimizes Wellbore Tortuosity and Increases Directional Drilling Efficiency
Authors: Stroud D. , Peach S. , Johnston I. 
Published: January 2008

Abstract
Maintaining wellbore quality, and in particular hole gauge, is crucial to the steering performance of point-the-bit rotary steerable systems (RSS).4
This paper describes how computer-based predictive modeling and full-scale laboratory drilling tests (conducted in horizontal concrete blocks) have been successful in optimizing bottomhole assembly (BHA) design in terms of directional steerability and hole quality. The modeled predictions were proven in the field as well as the laboratory.
The precise control of drilling parameters and formation characteristics achieved in these laboratory tests has also been important in comparing laboratory drilling results with BHA software modeling predictions. Excellent correlation between BHA modeling and practical (laboratory and field) tests are obtained, resulting in data that is believed unique in the literature.4
Two distinct areas of BHA optimization related to the steering performance of an RSS in 6 1/8-in. hole were investigated.
Crosslinked Cements Solve Lost Circulation Problems
Authors: Mata Freddy , Veiga Manuel 
Published: January 2008

Abstract
A novel alternative has been developed to solve severe lost circulation problems. Cross linked cements (CC) can help to seal temporarily or indefinitely critical intervals where drilling and cementing operations are very difficult to be successfully accomplished due to severe lost circulation. The system can be designed in two versions, the first is a Magnesia cross linked cement (MCC), up to 98% soluble, especially designed to be used in pay zones, the second, a low cost alternative, is a regular cross linked cement(RCC) which is 73% soluble and is appropriate for sealing non- productive intervals. Positive results have been observed in field applications of both systems.
Gravel Packing Deep Water Long Horizontal Wells Under Low Fracture Gradient
Authors: Chen Zhongming , Novotny Rudolf J. , Farias Rodrigo , Mendez Alfredo , Pedroso Carlos A. , Fernandes Lucia Helena C. 
Published: January 2008

AbstractThe economics of the oil and gas production requirements and advanceddrilling technologies are often pushing the length of horizontal well to newrecords. Gravel packing these very long horizontal wells present new challengesto completion operations. The combination of long horizontal sections ofunconsolidated formations, low fracture gradients and costly rig time are theother constraints that must be faced in the design and execution of asuccessful gravel packing completion offshore. Innovative technologies, optimized job design and planning are the keys for the success of packingjobs.This paper addresses several key factors that must be considered carefullyin installing a successful gravel pack completion. Pack completion requiresthat these low fracture gradient wells not be fractured during gravel placementto avoid excess leakoff and premature screenouts. The discussion includesvarious measures such as optimized screen wash pipe annulus and appropriateusing the differential valves, to effectively reduce frictional pressure duringBeta wave buildup. Fluid leakoff and leakoff control, in-situ gravelconcentration, and their relationship are also discussed. The gravelconcentration is dynamically changing through out the treatment based on theflow conditions in the wellbore, especially when the gravel starts to packaround screen. While most of the fluid travels down the screen-casing annulus, portion of the fluid leaks into formation, portion of the fluid diverges intothe screen-wash pipe annulus. The results may be an effective in-situ gravelconcentration higher than critical concentration, forcing gravel particledeposition to occur too soon and building up a premature bridge.Several job designs and application histories are also presented in thepaper to demonstrate the design considerations and valuable lessons learnt. Agroup of type curves are generated for a quick and easy check during joboperation, if any undesired condition is present, the operator can adjust theoperation and thus to avoid a job failure. The overall system of fluid dynamicsare discussed and treatment guidelines are presented to provide the CompletionEngineers the necessary information for designing successful treatments.
Reservoir Management Optimization Using Permanent Downhole Gauge Data
Authors: de Oliveira Silva Márcia Ida , Kato Edson Tsuneo 
Published: January 2008

Abstract
Petroleum field exploitation on deep-water environment requires well completion strategy that minimizes the number of workover operations and provides an efficient reservoir data acquisition system to support field management decisions. This paper presents a Petrobras field experience in integrating monitoring data into reservoir management optimization on Campos Basin, Brazil.
The field development plan comprised satellite wells completed with wet-Xmas tree and producing with independent flowlines to a FPSO. To ensure an adequate monitoring data program1, all wells were equipped with permanent temperature and pressure sensors at downhole (PDG), wet-Xmas tree and production header.
The anticipated production program generated a huge high-frequency database during the initial field development plan implementation. Additional time-lapse data obtained from new drilled wells during field development increased reservoir knowledge about reservoir depletion, compartmentalization, barriers, waterflood efficiency, etc. Until nowadays data from PDG and time-lapse data allow frequent updates of the geological and reservoir flow model, reducing the project uncertainties.
The challenge is to incorporate these data into reservoir management optimization at the right time without loosing the economic opportunity window.
The strategy adopted has been considered efficient to face the preeminent decision making required by this type of reservoir in a deep-water field under anticipated production.
Application of Fuzzy Logic for Determining Production Allocation in Commingle Production Wells
Authors: Widarsono B. , Atmoko H. , Robinson W. , Yuwono I. P. , Saptono F. , Ridwan Ridwan 
Published: January 2008

Abstract
For oil or gas fields with stratified reservoir layers, detailed production contribution for individual layer is always desired. Unfortunately, in some particular cases, production wells are completed following commingled scheme. This is worsened further if only very few production tests are run for the field. This is the case for the Central Sumatera field with its 95 commingled production wells, among which only a few had undergone production tests and none of them have ever undergone production logging. Problems rise when the occassion came in which detailed production contribution from individual reservoir layer is required for the field's reservoir simulation modeling and production evaluation/prediction.
This paper presents an approach to solve the problem. The approach is basically based on the application of soft computing (Fuzzy Logic) to investigate pattern of relationships between production contribution of layers in commingle wells and rock petrophysical data as well as other relevant geological/engineering data. For the purpose, thirteen wells (key wells) that have production tests are assigned, among which three wells are assigned for checking the validity of the recognised pattern. Using the validated most valid pattern, individual layer's production allocation for other wells are determined with well-log analysis data as the major input.
Result estimates for the candidate wells are better compared to results produced by the conventional method of productivity index (PI) analogy. The resulted variation in water cut and separate oil and water split factors appear to be more realistic from any point of view.
Satisfying Profitability and Non-Flaring Gas Policy in an Emerging Gas Market Context: A Case History
Authors: Boni G. , Castano D. , Dresda S. , Esor E. , Monico C. 
Published: January 2008

Abstract
A zero gas flaring target was established by Nigeria based on the Kyoto Protocol, meanwhile a gas market was emerging in the Country.
This paper deals with a Nigerian onshore multilevel oil field on production for thirty-one years, where the associated produced gas was flared except a part that was re-injected.
An integrated revision study was carried out to investigate the possibility to improve the oil recovery and simultaneously honour the target of not flaring the gas and seize the gas market opportunity.
Several scenarios were studied based on the main alternative concepts to increase the gas injection activity or change the drive mechanism by performing the water injection, with the fixed constraint of not flaring the gas. An upgrade of the existing gas compression unit was required for the gas injection option, whilst a new plant was necessary for the water injection option. The benefit of higher oil recoveries due to gas injection and the advantage of larger gas amounts for the market in the case of water injection were assessed through the economic evaluation.
The highest profitability was achieved in the case of a gas injection increase followed by the conversion of the injectors into gas producers and was the consequence of the gas sale, which largely compensated the shortfall in oil recovery.
The conclusion was that it was possible to satisfy both the zero gas flaring requirement and the economic profitability through the opportunity of the gas market.
A lesson learnt was that the technical results based on the oil recovery alone were not enough to select the optimum development scenario, since the overall economic evaluation played the fundamental role.