bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Completion Technology Eliminates Formation Damage and Reduces Rig Time in Sand Control Applications
Authors: Garfield Garry , McElfresh Paul 
Published: December 2007

Abstract
Among the highest risks in well completions is formation damage caused by perforating. Fractured and compacted zones, perforation gun debris, and broken formation blockages are common types of damage that can occur inside the perforation tunnel. Reducing or eliminating initial perforation damage can result in a more productive well over its lifetime.
This paper examines a completely new technology for completing wells in unconsolidated formations that installs a liner hanger and sand control mechanism in a single trip to eliminate explosive perforation charges and associated formation damage risk. This new technology was developed by a Joint Investment Project (JIP) that included three major operators, a large service provider and a small technology company. In addition to eliminating perforating, the technology reduces the cost of well construction by allowing the production liner, flow conduit, primary cementing, and sand control tools to be run in a single trip.
The perfless completion system uses telescoping tubes that extend from the liner into the formation by applying hydraulic pressure and mechanical force. Once the tubes are extended (or telescoped), the liner is cemented in place. The tubes, which contain sand control media, form conduits from the formation to the casing ID. No large, high-horsepower fluid pumping treatments are required. Neither are after-completion drilling mud and fluid-loss control measures, both of which can cause formation damage.
The new completion method eliminates gravel packing and minimizes intervention in completion operations, saving substantial rig time. It also simplifies operation logistics, especially in remote or offshore environments.
This paper describes initial field test results of the new system, cost comparisons with existing methods, and expected economic benefits over the lifetime of wells in typical applications of this new technology.
Field Experience: First All-in-One Machine for Making Up Drillstring, Bottomhole Assemblies, Casing, and Tubing in the Norwegian Sector
Authors: Abrahamsen Egill , Trulsen Alf Arne 
Published: December 2007

Abstract
A new-generation, multifunctional iron roughneck was installed and operated on the ULA platform in the North Sea, offshore Norway, in 2003. This iron roughneck is unique in its ability to make up and break out a vast variety of drillstring components without personnel on rig floor, and it accommodates remotely operated power tongs for casing and tubing running by simple exchange of tong modules inside the roughneck carrier. The iron roughneck included such features as a new integrated mud bucket, a cleaning and doping device for drillpipe (tool joint box), and a stabbing guide.
All of these features contributed to a safer rig floor operation, but they also enabled a streamlined interface with rig floor operations without a multitude of control panels and interfaces. The operator initially rented the equipment, which replaces traditional iron roughnecks, for a one-well program but decided to purchase the system for subsequent drilling operations.
This paper discusses the rationale for selection of the equipment for the ULA project; the operator's expectations; installation, interface, start-up, and operational experience from the ULA platform; and success of the equipment in meeting Norwegian authorities' more stringent requirements for remote operation.
Improving the Reliability and Availability of Dynamic Positioning Systems
Authors: Fougere Peter 
Published: December 2007

Abstract
While Dynamic Positioning (DP) system reliability currently is at historical peak performance levels, opportunities exist for additional improvement. The following three improvement areas are based on findings from a review of available DP Event Reports. The first two areas involve Failure Mechanics and Effects Analysis (FMEA), which is the main tool used for assessing equipment reliability. The third finding covers training of DP Operators (DPOs). A review of existing DP FMEAs showed inadequate depth of execution in many cases, while others did not comply with existing industry FMEA standards. A specification was developed to raise the scope and quality of DP FMEAs. The specification will be used to perform new FMEAs on existing vessels. We expect the new FMEA studies will demonstrate higher effectiveness of finding potential DP reliability problems.Utilizing FMEA techniques and our fleet experience, we are preparing Guidelines for Reliability and Availability of power plant and thrusters. They will be used to assess existing systems for upgrade and for the basis of design for any new vessel.Human error accounted for some portion of most DP events. Our assessment showed that the standard industry wide training for DP Operators (DPOs) is not fully adequate. A series of efforts identified what a DPO needs to know, prepared a DPO development plan to match the needed knowledge, and developed a DPO competency assessment scheme.
Applicability of the VAPEX Process to Iranian Heavy Oil Reservoirs
Authors: Azin R. , Kharrat R. , Ghotbi C. , Vossoughi S. 
Published: December 2007

Abstract
The objective of this paper is to evaluate the viability of the VAPEX process for an Iranian heavy oil reservoir according to the reservoir characteristics. Also, based on the reservoir fluid conditions, the optimum solvent system to meet the requirements of the VAPEX process is determined. In addition, a mechanistic model was developed for the study of the VAPEX process by considering the mass transfer and fluid flow mechanisms characteristics of the VAPEX process. The model is capable of predicting the drainage rates of heavy oil in all stages of the process, including the pseudo-steady state. Also, various initial and boundary conditions can be specified to the model. The results obtained by this model agree well with the experimental data. The model was further applied to a fractured system and effects of solvent injection rate, fracture and matrix permeability, matrix to fracture permeability ratio, and initial viscosity of the reservoir heavy oil on the performance of the VAPEX process were studied.
Development of the Ultimate Ultra Harsh Environment Jack-up Drilling Rigs
Authors: Smidth Frederik , Wullf Per 
Published: December 2007

Abstract
Drilling with jack-ups in harsh environments has moved into deeper and deeper water during the last 10 years.
Previously 90 m was considered the maximum whereas up to 150 m water depth is now feasible.
In addition several new features are now available on harsh environment jack-ups which increase the drilling efficiency by up to 25% compared with the more conventional jack-up types.
This paper describes the process of creating the next generation deepwater jack-up drilling rig, and the results and operational experience with the Maersk "I" class rigs-the Maersk Innovator and the Maersk Inspirer.
The Maersk Innovator has been in operation for approximately 18 months and the Maersk Inspirer is in transit to the North Sea. The Maersk Inspirer is contracted to start operating in February 2005.
Upscaling Fracture Networks for Simulation of Horizontal Wells Using a Dual-Porosity Reservoir Simulator
Authors: Ding Y. , Basquet R. , Bourbiaux B. 
Published: December 2007

Abstract
One difficulty in fracture upscaling for field-scale dual-porosity reservoir simulation is the determination of equivalent gridblock fracture permeability, which depends on the type of boundary conditions imposed on the discrete fracture network (DFN) simulation. Actually, classical upscaling procedures are usually based on linearly-varying pressure boundary conditions, which cannot capture the near-well flow behavior. As a result, the well productivity calculated by a dual-porosity flow simulator can be very different from that calculated on a DFN model.
This paper proposes a near-well fracture upscaling procedure based on the geological DFN model to improve the accuracy of well productivity in fractured reservoir simulators. This procedure enables to represent the actual flow through the fractures and the exchanges between matrix and fractures in the well vicinity. Based on the computed near-well flow pattern, equivalent fracture transmissibilities as well as numerical well indices are determined and assigned to the gridblocks of dual-porosity reservoir simulator. Efficiency and necessity of using near-well upscaling procedure are demonstrated by examples.
Sequence Stratigraphy and Reservoir Characterization of the 2nd Eocene Dolomite Reservoir, Wafra Field, Divided Zone, Kuwait-Saudi Arabia
Authors: Wani M. Rafiq , Al-Kabli S. Khalil 
Published: December 2007

Abstract
The 2nd Eocene dolomite reservoir is one of the major producers in the giant Wafra Field of the Divided Zone between Kuwait and Saudi Arabia. The reservoir is of Paleocene age and occurs in the Tertiary Umm Er Radhuma Formation. The reservoir has been producing since late 1950's primarily under depletion drive. Recoveries, however, remain poor (about 5% of OIIP) mainly due to low-gravity oil and reservoir heterogeneity. A geological model that better defines reservoir heterogeneity is a pre-requisite for evaluating and implementing EOR techniques.
Primary porosity in subtidal dolomitized carbonates associated with evaporites, as well as its later modification by dolomitization, dissolution and cementation, typically occurs in multiple zones formed within shallowing upward cycles. This paper attempts to identify such high frequency cycles in the Wafra 2nd Eocene Reservoir and place them in a sequence stratigraphic framework. Based on core analysis, and well log correlations in more than 300 wells, eight high frequency cycles further divided into 15 ‘zones' are recognized. This zonation helps to define the better and poorer reservoir units and the intervening non-reservoirs in a systematic manner as it brings out the distribution of grain rich dolomites and evaporites, as well as the cyclicity of dissolution and cementation. This has helpedin improving reservoir definition over the entire field and led to a more robust stochastic model.
Efficient Three-Dimensional Implementation of Local-Global Upscaling for Reservoir Simulation
Authors: Wen X. -H. , Durlofsky L. J. , Chen Y. 
Published: December 2007

Abstract
Upscaling is often applied to coarsen detailed geological reservoir descriptions to sizes that can be accommodated by flow simulators. Adaptive local-global upscaling is a new and accurate methodology that incorporates global coarse scale flow information into the boundary conditions used to compute upscaled quantities (e.g., coarse scale transmissibilities). The procedure is iterated until a self-consistent solution is obtained. In this work, we extend this approach to three-dimensional systems and introduce and evaluate procedures to decrease the computational demands of the method. This includes the use of purely local upscaling calculations for the initial estimation of coarse scale transmissibilities and the use of reduced border regions during the iterations. This is shown to decrease the computational requirements of the reduced procedure by a factor of about six relative to the full methodology, while impacting the accuracy very little. The performance of the adaptive local-global upscaling technique is evaluated for three different heterogeneous reservoir descriptions. The method is shown to provide a high degree of accuracy for total flow rate, local flux and oil cut. In addition, it is shown to be less computationally demanding and significantly more accurate than some existing extended local upscaling procedures.
Conditional Statistical Moment Equations for Dynamic Data Integration in Heterogeneous Reservoirs
Authors: Li L. , Tchelepi H. A. 
Published: December 2007

Abstract
We present an inversion method for the integration of dynamic data directly into the statistical moments of the dependent variables, such as pressure, for flow in heterogeneous porous media.
We consider the problem of incompressible Darcy flow in a heterogeneous domain. We assume that a few measurements of permeability are available and that the mean, variance, and correlation structure of the permeability field are known. In addition, we assume that a few measurements of the dependent variable, e.g. pressure, are available. The first two statistical moments of the dependent variable (pressure) are conditioned on all available information directly. The approach is based on applying an iterative inversion scheme to integrate dynamic data into the conditional statistical moment equations (CSME). That is, in addition to statistical information about the permeability field, measurements of static (permeability) and dynamic (pressure) variables are used to condition, or improve the estimates of, the mean and second moments of pressure and velocity directly. This is different from Monte Carlo (MC) based geostatistical inversion techniques, where conditioning on dynamic data is performed for one realization of the permeability field. In MC based schemes, estimates of the prediction uncertainty are obtained from statistical postprocessing of a large number of inversions, one per realization.
Our moment-based dynamic data integration method is demonstrated using several examples of flow in heterogeneous domains in a quarter-five-spot setting. We show that as the number of pressure measurements increases, the conditional mean pressure exhibits more spatial variability while the conditional pressure variance becomes smaller. Our experience indicates that iteration of the CSME inversion loop is only necessary when the pressure measurements deviate significantly from the prior (conditional) expectations. We also discuss how the CSME flow simulator can be used to assess the value of both static and dynamic information, measured in terms of reduction of prediction uncertainty.
The Use of Parallel Processing with Dynamic Gridding
Authors: Darche G. , Grabenstetter J. E. , Sammon P. H. 
Published: December 2007

Abstract
There has been considerable interest shown in the use of dynamic gridding techniques for isothermal and thermal compositional simulation. These techniques allow simulation grids to adapt to the physics of complex EOR processes, while retaining a high degree of computational efficiency through the use of relatively coarse grids in areas where there is little activity. Since areas of interest in reservoir models change with time, simulators that use dynamic gridding techniques must be able to deal with changing internal pointer systems as a regular occurrence in their calculations.
There also has been interest in the use of shared memory parallel computers that achieve computational efficiency through the use of various techniques for overall simulator parallelization, as well as for the use of suitable reservoir splittings and associated multi-coloured orderings for ILU linear solvers. These splittings are usually based on some kind of regular cell-based splitting of the reservoir. Unfortunately, such splittings do not immediately apply to the unusual grids generated by dynamic gridding schemes, which exhibit multi- level refinements that are constantly changing.
The goal of this paper is to examine alternate solver orderings based on novel applications of reservoir splittings and also to examine orderings that are applicable to more general systems, such as orderings arising from graph- theoretic notions. The paper will give an overview of different ordering strategies for the parallel linear solver, and will examine how they fare when faced with complex compositional field examples. Results will be shown that indicate that the benefits of dynamic gridding and of the use of a parallel ILU solver can be simultaneously realized in simulations of complex EOR processes. The combination allows for more detailed simulation work and the possibility of working with more reservoir realizations, greatly enhancing the understanding of complex reservoir processes.
Multilevel Fracture Network Modeling of Naturally Fractured Reservoirs
Authors: Kazemi H. , Atan S. , Al-Matrook M. , Dreier J. , Ozkan E. 
Published: December 2007

Abstract
This paper provides a review of common approaches for simulation of naturally fractured reservoirs and a new model formulation that is more amenable to the utilization of detailed geologic information from deterministic models, multipoint statistical simulations (MPS), and discrete fracture network (DFN) models. Unlike the common dual-porosity and dual-permeability models, the new model considers flow in several sets of fractures (that is, micro, macro, and mega fracture levels) and the wells can intercept any class of fractures. Matrix flow is also included in the formulation. A dual-mesh-computing algorithm is used to capture the major orientation of fractures in the flow network. The algorithm consists of the conventional five-point discretization for the coarse grid and a special nine-point discretization scheme for the fine grid. The size of the coefficient matrix for the discretization scheme can be reduced because of the dominance of vertical flow drainage in fractured reservoirs.
A Novel Approach to Wireline Logging in Directional Wells and Difficult Logging Conditions
Authors: Boyes J. S. , Elkington P. A. S. 
Published: December 2007

Abstract
Conventional wireline logging has always faced the challenge of obtaining data in highly deviated wells, horizontal wells and those with bad hole conditions. Typical solutions included pumping down tools through open end drillpipe, drillpipe conveyed wireline logging, coiled tubing conveyed wireline logging or ultimately Logging-While-Drilling.These operations are time consuming and costly.
A new openhole memory logging system was introduced in 2000, initially as a more efficient alternate to pipe conveyed logging in such wells.Extensive field-testing of this system over the last few years has yielded a series of technical developments that has evolved into a low cost and unique formation evaluation logging system.This system combines memory logging with a novel deployment system that yields a cost effective approach to obtaining high quality formation evaluation data.Obtained post-drilling, the shuttle system conveys memory logging tools rapidly to TD inside the drillpipe as part of a wiper trip or check trip.
Logging tools used in this system are designed to be extremely short and small diameter (2.25").The system is battery powered and includes a wide variety of capabilities including quad-combo measurements and, in the near future, repeat formation pressure testing.Logging tools are conveyed to TD inside the drillpipe.Once at TD, an electro-mechanical pressure activated release mechanism moves the tool string from inside the drillpipe into the openhole.A landing collar and latch mechanism maintains a mechanical connection between the top of the tool string and the shuttle system that remains connected to the drillpipe.A pressure signaling system not only controls the tool release but also provides simple two-way communications - a key element in providing real-time QA in the memory repeat formation pressure tester operations.Examples will be shown where these systems have demonstrated to be cost effective.
Energy Conservation Through the Implementation of Cogeneration and Grid Interconnection
Authors: Dashash M. A. , Mahfoudhi R. 
Published: December 2007

Abstract
With increasing awareness of Energy Conservation and Environmental Protection, the Arab World is moving to further improve energy efficiency.
The equivalent of over 2.6 MM bbl is being daily burnt to fuel the thermal power plants that represent 92% of the total Arab power generation. This adds up to close to one billion barrels annually.
In this paper we will introduce two strategies with the objective to cut-off up to half of the current fuel consumption.
Firstly, by improving the thermal efficiency. It is proven now, that cogeneration technology is able to bring the efficiency from the current average of less than 25% to up to 80%.As an example we will present the case of Saudi Arabia experience of implementing cogeneration, in particular within its hydrocarbon facilities and Desalination Plants.
Secondly, by interconnecting the power networks of all adjacent Arab countries. At least 2 factors plead for this direction. On one hand, the 4-hour time zone difference from Eastern to Western Arab World makes it easy to exchange power during peak and low demand periods. On the other hand, this will help to reduce the reserve capacity and save on corresponding capital investment, fuel, and O&M expenses.
Reaching the mentioned objectives is not only a major contribution to Energy Conservation, but also leads intrinsically to higher Environmental Protection.
Uncertainty Estimation in Production Predictions Constrained by Production History and Time-Lapse Seismic in a GOM Oil Field
Authors: Litvak M. , Christie M. , Johnson D. , Colbert J. , Sambridge M. 
Published: December 2007

Abstract
Successful uncertainty quantification requires many reservoir models matching field production data and time lapse seismic. We have been able to automatically generate nearly 50 history matched models for a GOM oil field using the Neighbourhood Approximation stochastic sampling algorithm. This allows us to produce uncertainty forecasts for various production scenarios.
Geostatistical simulation constrained by well log, core, and seismic data is applied for building geological and reservoir models. The parameters of the geostatistical simulation (channel directions, channel dimensions, variagram parameters, etc.) are considered as uncertain parameters. Additionally, end points of relative permeability curves, dependencies of compressibility factors and permeability on effective stress, transmissibility multipliers across faults, and water aquifer size are varied in the history matching process.
A misfit function is selected to quantify history match of model results with field measurements of water cut, gas-oil ratio, and reservoir pressure in production wells in different moments of time. Trends and variances of the observation data are determined and incorporated in the objective function.
The position of the water-oil contact at the beginning of the field development and after three years of production is estimated from time lapse seismic. Differences in the water-oil contact positions determined from the reservoir simulation and time lapse seismic are quantified and incorporated in the objective function.
The reservoir model has been run nearly 2400 times in the history matching process. The Neighbourhood Algorithm is applied for the selection of the values of the history matching parameters in each run. The high quality of the history match is demonstrated,
An ensemble appraising procedure based on a Bayesian framework is used to determine probability distributions of the history matching parameters and to assign probabilities to the simulation models (runs). About 50 models with the highest probabilities (which cover 99% of the cumulative probability range) are selected for the predictions. A general tool has been developed for the definition of statistical parameters of production predictions (mean values, confidence interval, etc) and their changes in time. Uncertainty estimations for the base case predictions and several production scenarios are demonstrated.