bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Development Optimization Technology
Authors: Litvak Michael , Gane Brian , Williams Glyn , Mansfield Mark , Angert Patrick , Macdonald Chris , McMurray Lesley , Skinner Roger , Walker Greg J. 
Published: December 2007

Abstract
This paper describes the development and application of a new field development technology to optimize the locations of new and sidetracked wells within an oil or gas field, the drilling schedule, water and gas injection strategies, production/injection rates, and surface facilities. The field development plan optimization is informed using BP’s Top-Down Reservoir Modeling (TDRM) methodology. An economic indicator (e.g. net present value, incremental rate of return, capital efficiency, discounted payback, etc.) or oil/gas recovery is maximized subject to field development constraints. Only drilling targets in geologically defined areas are considered. Sidetrack wells are additionally limited by distance from their parent well. Drilling rig constraints (rig availability, drilling time, drilling costs, etc.) are incorporated. Economic constraints on project costs are also taken into account.
Multiple integrated reservoir models, representing different combinations of sub-surface description and surface facilities, can be handled within this new field development optimization system. The system generates the optimum field development option by maximizing a percentile of either the selected economic indicator or the oil/gas recovery. Associated risks can be considered as constraints. Probability distribution functions of the maximized objective function and associated constraints are determined with a powerful optimization procedure developed using a combination of public and proprietary techniques. A large range of field development issues from well locations, drilling schedule, injection strategy and facilities modifications can be addressed.
Applications of the developed technology for field development optimization in a giant new offshore oil field, and a mature oil field are presented. These applications clearly demonstrate that the new development optimization technology is a sufficiently general tool for analysis to inform field development planning. Significant improvements in oil recovery, sweep efficiency, and net present value are demonstrated in the comparison with the reference field development cases.
A New Finite-Volume Approach to Efficient Discretization on Challenging Grids
Authors: Aavatsmark I. , Eigestad G. T. , Heimsund B.–O. , Mallison B. T. , Nordbotten J. M. , Øian E. 
Published: December 2007

Abstract
MPFA methods were introduced to solve control-volume formulations on general simulation grids for porous media flow. While these methods are general in the sense that they may be applied to any grid, their convergence properties vary.
An important property for multiphase flow is the monotonicity of the numerical elliptic operator. In a recent paper [1], conditions for monotonicity on quadrilateral grids have been developed. These conditions indicate that MPFA formulations which lead to smaller flux stencils are desirable for grids with high aspect ratio or severe skewness and for media with strong anisotropy or strong heterogeneity. The ideas were recently pursued in [2] where the L-method was introduced for general media in 2D. For homogeneous media and uniform grid, this method has four-point flux stencils and seven-point cell stencils in two dimensions. The reduced stencils appear as a consequence of adapting the method to the closest neighboring cells
Here, we extend the ideas for discretization on 3D grids, and ideas and results are shown for both conforming and nonconforming grids. The ideas are particularly desirable for simulation grids which contain faults and local grid refinement.
We present numerical results herein which include convergence results for single phase flow on challenging grids in 2D and 3D, and some simple two-phase results. Also, we compare the L-method with the O-method.
A Study of Acid Cement Reactions Using the Rotating Disk Apparatus
Authors: Nasr-El-Din H. A. , Al-Yami A. , Al-Aamri A. , El-Marsafawi Y. 
Published: December 2007

Abstract
Cement is extensively used for zonal isolation. This cement comes in contact with corrosive fluids during matrix treatments to the formation. Acids can react with various components present in cement and cause severe damage to cement. The damage depends on cement type, acid type and concentration, temperature, pressure, surface area, and exposure time. Previous studies on cement acid reaction are sparse and typically use a 2"x2"x2" cubes soaked in acid under static conditions. The objective of the present work is to examine the acid cement reactions under dynamic conditions.
The reaction between regular cement (118 pcf) and HCl was examined using the rotating disk apparatus. Cement disk 1.5 inches in diameter and 0.6 inch in thickness were used. The effect of disk rotational speed (0 to 1,000 rpm), on the dissolution rate of regular cement was determined. The system pressure was maintained at 1,000 psi and the reaction was allowed to proceed for 120 minutes. Samples from the reaction vessel were collected at various times and were analyzed for various key cations using inductively coupled plasma emission spectroscopy (ICP).
The results obtained indicated that HCl acid leached calcium, iron and aluminum from the cement disks. The concentrations of these ions increased with time. Calcium concentration was significantly higher than other cations. The reaction rate was controlled by diffusion of H+ to the surface of cement. This paper will discuss the results obtained and address their implication on field applications.
Chemical Diversion Techniques Used for Carbonate Matrix Acidizing: An Overview and Case Histories
Authors: Chang Frank F. , Qiu Xiangdong , Nasr-El-Din Hisham A. 
Published: December 2007

Abstract
The purpose of matrix treatments in carbonate reservoirs is to increase connectivity of a formation with the wellbore in the entire zone of interest. Successful matrix treatments depend on the uniform distribution of the treating fluid over the entire interval. When fluids are pumped into a well, they naturally tend to flow into the zone with the highest permeability or least damage. Field experiences showed that there is no assurance of complete zone coverage without proper diversion. Therefore, diversion is recommended in all treatments, especially in extended reach and multi-lateral wells.
Diversion techniques can be classified as mechanical or chemical. Mechanical control of treating fluid placement can be accomplished by coiled tubing with an inflatable packer, or with conventional straddle packers or ball sealers. Although mechanical techniques are very effective, they are more expensive and time consuming than chemical techniques and they are often not applicable or not effective in wells with open-hole completion. More importantly, mechanical means diverts treatment fluids from the wellbore; however, there is no control once the fluid enters the formation. Chemical diversion can be achieved through placing a viscous fluid, foam or gel to lower the penetration of treatment fluid in the created wormholes and their surrounding matrix, or a particulate carrying fluid, which creates a filter cake on the surface of the wormholes. This filter cake results in temporary skin effect which alters the injection profile. Gelled and foamed acids are also being used as a means of improving acid placement by combining stimulation and diversion in one step.
Diversion is a critical step to ensure the success of matrix acid treatments. Understanding how chemical diverters interact with the formation rock and fluid is the key to selecting the proper product for a specific treatment. It is the intent of this paper to provide a technical overview of mechanical and chemical diverters used in the oil industry. The various mechanisms by which these chemicals to achieve acid diversion, their application histories, and their limitations are presented. This paper provides guidelines for production engineers to optimize the fluid placement.
Advances in Microbial Ecology Relevant to the Application of Nitrate to Control Reservoir Souring
Authors: Maxwell S. 
Published: December 2007

Abstract
During the 1980’s, studies initiated to resolve problems due to the activity of sulfate-reducing bacteria in oilfield systems were instrumental in the early recognition of the importance of biofilms in natural environments, the use of radiotracers to measure bacterial activity, the application of molecular techniques to study non-culturable bacteria and the detection of previously unknown Archaea in subsurface aquifers.
Over the past 15 years, however, oilfield microbiology practices have not kept pace with other fields of environmental microbiology research and now the ideas and practices applied in the oilfield lag significantly behind the most recent scientific advances. This is despite the fact that the oil industry is currently attempting to control very diverse and extensive sulfide producing microbial populations by the application of nitrate to bring about a shift in the population dynamics in a process of biological competitive exclusion.
Environmental microbiology is now in the midst of a revolution in the understanding of the marine and subsurface microbial world, much of which is resulting in completely new concepts of the interaction between microbes and the environment and vice versa. These advances must be recognized and wherever possible incorporated into oilfield microbiology technology.
This paper describes how the application of even a few of the recent advances in environmental microbiology offers a huge potential to improve our understanding of control and remediation of sour reservoirs using nitrate treatments.
Assessment of Barite Scaling Potentials, Sulfate Removal Options, and Chemical Treating Strategies for the Tombua-Landana Development
Authors: Chen Huey J. , Hinrichsen Charles J. , Burnside Christopher A. , Widener Mark 
Published: December 2007

Abstract
This paper discusses the development of a holistic water and scale management plan for a green-field development, which faces a new order of scale management challenges. Specifically, this paper documents a scale risk assessment and the development of a scale management plan during the front-end engineering design of the Tombua–Landana development in West Africa. The complexity of scale management is compounded by the presence of multiple reservoirs with very different scaling potentials and by the plans for produced water reinjection. The objective of the study was to define a complete scale management plan, which incorporates flexibility for future unknowns and minimizes the total cost of scale management, without over-capitalization.
The Tombua-Landana field will produce from multiple reservoirs that incorporate several distinct formation waters with barium content as high as 800 mg/l and will require seawater injection for reservoir pressure maintenance from day one. Scaling tendency predictions were made for the major groups of formation water, both with and without seawater injection. In addition, a variety of produced water reinjection scenarios were investigated.
Due to the predicted severity of barite scaling, it was determined that scale would not be effectively controlled solely by scale inhibitor chemicals. It was therefore necessary to investigate alternative mitigation strategies, primarily sulfate removal. The impact of sulfate ion removal from seawater on barite scaling was investigated in order to determine the level of sulfate ion removal that would be necessary for each water type to limit the extent of scale deposition to a level that most residual scaling could be controlled by downhole chemical injection.
Because of the considerable cost associated with processing low sulfate injection water, it was necessary to optimize the size of the sulfate removal membranes (SRM) primarily by using produced water reinjection.
This field study typifies several industry trends in inorganic scale management: (i) Deepwater West Africa is emerging as a new focus area for sulfate scaling; (ii) Deepwater economics require co-production of multiple reservoirs in order to reach threshold reserves and will necessitate the installation of major infrastructures; (iii) Economic and environmental drivers support the use of produced water reinjection, even though this exacerbates water compatibility problems and creates new challenges for reservoir monitoring.
Unstructured Upgridding and Transmissibility Upscaling for Preferential Flow Paths in 3D Fractured Reservoirs
Authors: Vitel S. , Souche L. 
Published: December 2007

Abstract
Most existing upscaling methods attempt to evaluate effective permeabilities of coarse-scale gridblocks, so that the upscaled model locally reproduces the behavior of the fine-scale grid, under a set of boundary conditions. When applied to fractured reservoirs, this approach shows several drawbacks. First, it assumes the existence of a representative elementary volume (REV), which size is constrained by the practical needs for an efficient simulation. Yet, no REV exists for fractured systems which are characterized by a wide variety of fracture sizes. Second, the dynamic behavior of the model is unknown far from the applied boundary conditions. Third, this approach tends to underestimate the impact of steep pressure gradients that may occur between fracture and matrix media.
The presented method overcomes all three limitations by upscaling transmissibilities, so that the coarse-scale model preserves the same pressure response as the detailed geological model at a set of arbitrarily chosen observation points. A discrete fracture network and a corner-point grid are first jointly discretized using a dual approach (pipe network). Nodes of the pipe network represent either discrete fractures or matrix blocks. Pipes stand for matrix-to-matrix, fracture-to-fracture and matrix-to-fracture connections. Then, upgridding and upscaling are simultaneously performed, without imposing any boundary conditions: nodes are iteratively removed by applying electric simplifications (series, parallel, star-mesh transformations) until only the selected observation points remain. This process introduces new connections that may link nodes that were initially not connected, thus better modeling features such as super-K or large-scale fractures. This tends to convert a large sparse system into a smaller but fuller one; therefore parts of the network need to be lopped off before informing a flow simulator. Pipes holding the lowest transmissibilities are decimated and the remaining transmissibilities are updated accordingly in an optimization procedure. Flow simulation results obtained for several data sets on upscaled models are in good accordance with those obtained before upscaling, and show appreciable improvements compared to conventional structured local approaches.
Semistiff Carbon-Fiber Rod Pushed into Live Wells for Reservoir Performance Monitoring and Leakage Detection
Authors: Hansen H. , Wilberg T. , Naldrett G. , Meldrum N. 
Published: December 2007

Abstract
This paper describes how a patented intervention based DTS logging system can be used to address the many and varied reservoir management challenges faced in declining fields, complex well profiles and complex completion methodologies. A description of the prototype system is provided along with the test results from the test well, and full suite of a Data Management System for Data Acquisition, processing and capabilities for Reservoir Flow Analysis. The paper closes with a draft overview of where this technology may be in the near future.
Real-Time Monitoring: A Critical Review of a Multidisciplinary Collaboration Environment for Timely Business and Technical Decision Making
Authors: Tan EeVern , Kok Keng H. , Noor Harun M. , Noordin Khairul Annuar 
Published: December 2007

AbstractReal time solutions: an innovative approach to making business-time critical driven decisions. It is designed to monitor, support, and optimize operations in real time and remotely to mitigate cost and risk at work sites. The workflows allowed real time monitoring and intervention of the drilling operating parameters from the office which resulted in greater operating efficiency and thus greater financial saving. This technology was instrumental to the Angsi development team's success in drilling Malaysia's longest development well to-date, Angsi-A028ST1 at a total depth of 6,339 meters.Real time well construction workflows begin when real time data on the rig site are gathered and transmitted to PETRONAS Carigali Sdn.Bhd, PCSB office via VSAT link. Data can be accessed via a web-based interface for 24 hours coverage anytime anywhere. The real time data are integrated into a geological and geophysical project database and fed into a 3D visualization tool which amalgamates the planned and current well trajectories within the geological earth model incorporating neighbouring wells with operations data. The simultaneous display of "knowledge-management-cubes" from daily drilling operational reporting software enables the team to review contingency plans and be pre-emptive by the captured lesson learnt.This technology creates multidisciplinary collaborations through the ether space, reducing communication gaps and greatly improving the decision making process. Examples: reducing the number of check trips, shortening the planned TD by comparing the real time data against correlated model, and helping in handling operational problems. The team has greatly benefited from RTO - technologies, people and processes - with a total cost saving of more than USD 1 million.This paper presents the real time system setup, architecture and scope of work in enabling 2D and 3D well visualization and integration. The value-added and the relative cost savings, observations and feedback are also presented
Scaling of Thermodynamic and Transport Processes for Predicting Methane Hydrate Saturation in Marine Sediments Worldwide
Authors: Bhatnagar G. , Chapman W. G. , Dickens G. R. , Dugan B. , Hirasaki G. J. 
Published: December 2007

Abstract
Modeling the accumulation of marine gas hydrates has previously been attempted for specific sites with separate sources of methane, i.e. biogenic or upward flux from deeper sources. We have developed a numerical model in one spatial dimension that simulates the formation and accumulation of hydrates due to either or a combination of the two sources. The results are scaled using combinations of the dimensionless variables, such that the dependence of average hydrate saturation on the numerous parameters can be summarized using two contour maps, one each for in-situ and deeper methane sources. We also show points corresponding to well studied hydrate locations on these saturation maps. As compared to the earlier site-specific parameter studies, our model presents a unifying picture of hydrate accumulations, that can be used to predict hydrate saturations and distribution at sites for which seismic or core data is not available.
The Influence of Ultrasonic Energy on Capillary Fluid Displacement
Authors: Hamida T. 
Published: December 2007

AbstractIn recent years, field tests and laboratory investigations have demonstrated that high intensity acoustic stimulation may enhance oil recovery in rocks. This technology is not only technologically feasible, but also serves as an economical, environmentally friendly alternative to currently accepted EOR methods. It requires low capital expenditure, and yields almost immediate improvement without any additional EOR agents. Despite a vast body of empirical and theoretical support, this technology lacks sufficient understanding to make meaningful, consistent engineering predictions. This is in part due to the complex nature of the physical processes involved, as well as due to a shortage of fundamental/experimental research. Much of what we believe is happening within ultrasonically stimulated porous media is speculative and theoretical.This paper aims at identifying and analyzing the influence of high-frequency, high-intensity ultrasonic radiation on the miscible and immiscible displacement of oil in capillary media. We first investigate the effect of ultrasound on flow through a capillary via the pendant drop method. Water was injected into a capillary which is submersed into various processed mineral oils and kerosene. The average drop rate per minute was measured at several ultrasonic intensities, and we determined that there exists a peak drop rate at a characteristic intensity, which strongly depends on oil viscosity and the interfacial tension between water and the oil. The second set of experiments comprises of Hele-Shaw type experiments designed to study instabilities at liquid-liquid interface when ultrasound is applied. Fractal analysis techniques were used to quantify the degree of fingering and branching, allowing a rough assessment of the degree of perturbation generated at the interface. Miscible Hele-Shaw experiments are also presented to illustrate the effect of viscous forces alone. We found that ultrasound acts to stabilize the interfacial front, and that such effect is most pronounced at low viscosity ratios. The third series of experiments focuses on the effect of ultrasound on spontaneous (capillary) imbibition of an aqueous phase into oil-saturated Berea sandstone and Indiana limestone plugs. Both counter-current and co-current geometries were tested. Due to the intrinsically unforced, gentle nature of the process, and their strong dependence on wettability, interfacial tension, viscosity and density, such experiments provide valuable insight into some of the governing mechanisms behind ultrasonic stimulation.
Stereoscopic Endoscopic Optical System for 3D Measurement of Pipeline Welded Unions’ Internal Geometry
Authors: Hofmann A. C. Henri 
Published: December 2007

Abstract
During fabrication of Steel Catenary Risers, the welding process is considered critical to its lifetime. Control the girth weld misalignment during fabrication would improve fatigue performance.
The present work develops an optical system capable of quantifying the misalignment between the welded risers sections and to detect common geometrical welding defects like lack of fusion and excess of penetration utilizing a stereoscopic assembly.