bluuebunny/crossref_metadata_2025_split huggingface dataset:
Streamline-Based Method With Full-Physics Forward Simulation for History-Matching Performance Data of a North Sea Field
Authors: Agarwal Bijan , Blunt Martin J. 
Published: December 2007

SummaryWe present a method for history-matching production data using a streamline simulation that captures all the pertinent physics, including compressible three-phase flow with gravity. We use an approach based on the assumption of 1D flow along streamlines to find the sensitivity of water flow rate at production wells to changes in permeability. Although the computation of the sensitivities is approximate, we show, using data from a North Sea field, that the method can provide a reasonable history match and good predictions of future performance for problems with significant effects caused by compressibility and gravity.
Aspects of Hydrodynamic Loading in Design of Production Risers
Authors: Loken A.E. , Torset O.P. , Mathiassen S. , Arnesen T. 
Published: December 2007

This paper describes an experimental program undertaken to understand better the hydrodynamic loading of multitube production risers. Test results are described, and a generalization is given for engineering applications. Sample design calculations are performed.

Introduction
In recent years, much attention has been paid to analyzing the response of drilling risers. Most effort has been focused on the development of structural and analytical techniques to predict the stresses in riser systems. The analytical tools are, to a certain extent, calibrated by full-scale measurement. API published a comparison] of nine different, independent calculations of riser response that were in close agreement.Normally, drilling risers have a simple cross section for which the hydrodynamic forces are fairly well known. Extensive studies during many years have established insight into the flow patterns around a single smooth cylinder in constant flow and the corresponding forces. For multitube production risers the hydrodynamic load pattern is far more complex.Research is continuously improving the knowledge of flow-induced forces, particularly the influence of these parameters: high Reynolds number at prototype condition, effect of roughness, proximity effect of closely spaced cylinders, current/wave interaction, and effects of irregular seas.The state of the art regarding hydrodynamic loading on single cylinders in constant and oscillatory flow as a function of varying roughness has been published by Miller and Sarpkaya. Correspondingly, multiple cylinders have been considered by Zdravkovich, Bushnell, and Sarpkaya.To understand better the hydrodynamic loading of multitube production risers, Kongsberg Vapenfabrikk initiated an experimental program early in 1977. This program consisted initially of five riser configurations and one single cylinder to be tested in constant and oscillatory flow. A comparison with published data was made to check the experimental procedure and results against the state of the art. The experimental program later was extended by 18 additional geometries, sponsored by 10 oil companies as a joint industry program.The tests in constant flow were carried out at the Danish Hydraulic Inst. (DHI), while the oscillatory flow tests were performed at the Hydraulic Research Station (HRS). Det norske Veritas was consultant for the project and supervised the experimental work and the data interpretation procedures.This paper describes the experimental program, the test results, and a possible generalization for arriving at a simple engineering application of results.The discussion of sensitivity of important parameters in determining design loads is based on an actual design case. Design calculations performed by Kongsberg Vapenfabrikk for a production riser in deep water are presented.
JPT
P. 881＾
Canada's Pembina Field
Authors: Justen John J. 
Published: December 2007

Abstract
The Pembina field is the largest in Canada and one of the largest in the North American continent. Much of the published data concerning this reservoir is compared and summarized such that the geological, rock, and crude characteristics are indicated. The reservoir was initially undersaturated.
The production history is reviewed. The natural recovery mechanism is indicated to be solution gas drive. Engineering studies indicate that the ultimate recovery for various areas will be more than doubled if pressure is maintained by water flooding. With pressure maintenance the field will be in the billion barrel. reserve class. Pressure maintenance operations have commenced in various areas, using the existing wells in a 160-acre, five-spot pattern. A response to water injection has been reported in one area. By the end of 1957 about 50,000 acres will be under flood with water obtained from the North Saskatchewan River.

Introduction
In mid–1953 the successful completion of the wildcat, Pembina No. 1, recorded the discovery of the Pembina field. Today, four years later, one-fifth of Canada's daily crude oil production, and one-eighth of Canada's daily crude oil requirements are produced by the Pembina field.
The Pembina field is located in the Province of Alberta in Western Canada, 70 miles west-southwest from the city of Edmonton as indicated in Fig. 1. Its area, as defined by Alberta's Oil and Gas Conservation Board, is in the order of 400,000 acres. There are currently more than 1,750 producing wells representing 175,000 developed acres. The current production rate is over 110,000 BOPD. There are 43 operators in the field ranging from Mobil Oil of Canada, Ltd. which recently completed its 500th well, to Canadian Delhi, Ltd. with one well.
In area and production, this field is the largest in Canada. It is also one of the largest in the North American continent.

Geology
The reservoir is a stratigraphic trap resulting from the up-dip "shale-out" of the Cardium sand. The strike is slightly north of northwest and regional dip is to the southwest at a rate varying from 30 ft/mile in the northeast extremity of the field to 60 ft/mile in the southwest portion of the field. The Cardium sand is encountered at depths varying from 4,600 to 5,800 ft across the field. A contour map on top of the porosity is presented in Fig. 2.
Determination of Hydrocarbon Properties by Optical Analysis During Wireline Fluid Sampling
Authors: Dusen Alexandra Van , Williams Stephen , Fadnes Finn Hallstein , Irvine-Fortescue Jamie 
Published: December 2007

Summary
Recent innovations in wireline fluid sampling have allowed the expedient recovery of high-quality oil samples. The use of the Optical Fluid Analyzer† (OFA), a part of the Modular Formation Dynamics Tester† (MDT), to predict sample fluid type and quality has now become an essential part of the sampling process. The ability to use the optical data from the OFA in a more quantitative manner has been under development for several years. This paper demonstrates that the analysis of the optical spectra measured downhole can be used to give a quantitative indication of some hydrocarbon properties before or during sampling. Clearly, there are many potential benefits to be gained from using these optical spectra while sampling to assist in reservoir characterization and determination of oil type.
Optical data gathered while taking oil samples in 21 wells (drilled with water-based mud) offshore Norway were correlated with the pressure/volume/temperature (PVT) properties of those samples. The samples were selected to ensure a wide range of oil types to establish correlations between the fluid and optical properties. Correlations have been found between the optical response and some fluid properties, as determined from PVT laboratory measurements of the samples. Oil density, saturation pressure (pb), oil compressibility (co), formation volume factor (Bo), and gas/oil ratio (GOR) gave good correlations. Weaker correlations were found with other properties. The GOR and the optical responses could become measured variables with the possible future addition of a GOR measurement sensor to the MDT. Improved correlations are demonstrated when this feature is simulated. The results of this study show that the optical data measured during wireline fluid sampling can help determine key in-situ hydrocarbon properties.
Effect of Tool Joints on Contact Force and Axial-Force Transfer in Horizontal Wellbores
Authors: Duman O. B. , Miska S. , Kuru E. 
Published: December 2007

SummaryAn experimental study has been conducted to investigate the effect of tool joints on the buckling/post-buckling behavior of drillpipes constrained in straight horizontal wellbores. Buckling/post-buckling behavior of drillpipes has traditionally been investigated with continuous pipes. To our knowledge, this is the first time the effect of tool joints is included in such a study.The U. of Tulsa Drilling Research Projects experimental buckling facility has been used to carry out the desired experiments.Axial loads at both ends of the pipe and contact forces at the tool joints were measured. Changes in the drillpipe configuration were also investigated visually as the axial load increases.Some of the new findings of this study can be summarized as follows.Sequential occurrence of buckling/post-buckling configuration of jointed pipe is similar to that of continuous pipes, reported previously by various investigators. In other words, in both cases, the pipes buckle first laterally and then helically as the axial compressive load increased. The presence of tool joints does not affect the critical lateral (sinusoidal) buckling load significantly. However, it increases the critical load, causing helical pipe configuration (helical buckling) of approximately 20%. The use of tool joints improved the efficiency of the axial load transfer by approximately 40%.The results of this study will help to improve the design of operational parameters for drilling with jointed pipes as well as with coiled tubing (CT). In particular, improved axial-load transfer performance would allow drillers to use a higher weight on bit and, consequently, faster and possibly less costly drilling.
An Effective Continuum Model for the Gas Evolution in Internal Steam Drives
Authors: Tsimpanogiannis Ioannis N. , Yortsos Yannis C. 
Published: December 2007

Summary
We derive an effective continuum model to describe the nucleation and subsequent growth of a gas phase from a supersaturated liquid in a porous medium, driven by heat transfer. The evolution of the gas results from the reduction of the system pressure at a constant rate. The model addresses two stages before the onset of bulk gas flow, nucleation, and gas-phase growth. The problem arises in internal steam drive—for example, of the type recently discussed in blowdown experiments in carbonate rocks (Dehghani et al.,1 Dehghani and Kamath2).
Important quantities, such as the fraction of pores that host activated sites, the deviation from thermodynamic equilibrium, the maximum supersaturation, and the critical gas saturation depend crucially on the nucleation characteristics of the medium. We use heterogeneous nucleation models in the form of pre-existing gas, trapped in hydrophobic cavities, to investigate the nucleation behavior. Using scaling analysis and a simpler analytical model, we show that the relevant quantities during nucleation can be expressed in terms of a simple combination of dimensionless parameters, which include rate effects. The subsequent evolution of the gas phase and the approach to the critical gas saturation are also described using numerical and analytical models.
The theory predicts that the maximum supersaturation in the system is a weakly increasing function of the decline rate. This function depends sensitively on the probability density function of the nucleation cavity sizes. It also predicts that the final nucleation fraction, and thus the critical gas saturation, is a power law of the decline rate. The theory for both nucleation and phase growth is then compared with available experimental data.
New Analytical Solutions for Predicting Pressure Distribution and Transient Behavior in Wedges and Truncated Wedges
Authors: Rahman N. M. Anisur , Bentsen Ramon G. 
Published: December 2007

Summary
In most situations, predicting the pressure distribution and transient behavior becomes very difficult because of a lack of necessary mathematical solutions. However, analytical solutions are often used for such purposes, even though it may be necessary to compromise the geometry of the actual reservoir to obtain a solution. In this study, an integral-transform technique (ITT) has been used to develop new analytical solutions for pressure distribution in wedges and truncated wedges.
Optimization of Nonconventional Well Type, Location, and Trajectory
Authors: Yeten Burak , Durlofsky Louis J. , Aziz Khalid 
Published: December 2007

SummaryThe determination of the optimal type, location, and trajectory of a nonconventional well is extremely challenging. The problem is more complicated than other well optimization problems because of the wide variety of possible well types (i.e., number, location, and orientation of laterals) that must be considered. In this paper, a general methodology for the optimization of nonconventional wells is presented. The optimization procedure entails a Genetic Algorithm (GA) applied in conjunction with several acceleration routines that include an artificial neural network, a hill climber, and a near-well upscaling technique. The overall methodology is then applied to a number of problems involving different reservoir types and fluid systems. It is shown that the objective function (cumulative oil produced or net present value of the project) is always increased relative to its value in the first generation of the optimization, in some cases by 30% or more. The optimal well type is found to vary depending on the reservoir model and objective function. The effects of reservoir uncertainty are also included in some of the optimizations. It is shown that the optimal type of well can differ, depending on whether single or multiple realizations of the reservoir geology are considered.
Errors in History Matching
Authors: Tavassoli Z. , Carter Jonathan N. , King Peter R. 
Published: December 2007

SummaryThe usual procedure in history matching is to adopt a Bayesian approach with an objective function that is assumed to have a single simple minimum at the "correct" model. In this paper, we use a simple cross-sectional model of a reservoir to show that this may not be the case. The model has three unknown parameters: high and low permeabilities and the throw of a fault. We generate a large number of realizations of the reservoir and choose one of them as a base case. Using the weighted sum of squares for the objective function, we find both the best production- and best parameter-matched models. The results show that a good fit for the production data does not necessarily have a good estimation for the parameters of the reservoir, and therefore it may lead to a bad forecast for the performance of the reservoir. We discuss the idea that the "true" model (represented here by the base case) is not necessarily the most likely to be obtained using conventional history-matching methods.
Completion Design and Implementation in Challenging HP/HT Wells in California
Authors: Hahn D. E. , Burke L. H. , Mackenzie S. F. , Archibald K. H. 
Published: December 2007

Summary
As producing companies search for significant hydrocarbon resources, it has become necessary to pursue opportunities in frontier geologic horizons and geographic locations. This pursuit frequently results in encountering high-pressure/high-temperature (HP/HT) environments. The petroleum industry defines HP/HT wells as those exceeding 10,000 psi and 300°F.
Several companies have drilled into HP/HT horizons in the California San Joaquin basin in the past 30 years, but operations were generally halted because of equipment limitations or limited hydrocarbon indications. In late 1998, a significant gas flow was identified from the Temblor formation at depths lower than 17,100 ft, with geologic information indicating a potential Temblor sand gross thickness of up to 3,600 ft. The pressure design basis for subsequent wells assumed an estimated equivalent pore pressure of 16.9 lbm/gal. This information and other producing conditions indicated a potential bottomhole environment of 425°F and 18,000 psi. Produced fluids also indicated the presence of hydrogen sulfide (H2S), which, at these pressures, dictates sour service metallurgical specifications.
These potential, extreme well conditions require a very detailed completion engineering design, equipment qualification, rigorous planning, and precise field execution to achieve successful well completions. This paper details and discusses the well completion design basis and issues, equipment/perforating limitations and qualification tests, tubular stress and loading analyses, high-density completion-brine usage, and actual field operational experiences.
Numerous contingencies were planned in detail, some of which had to be implemented. The most significant contingency operation was a high-pressure coiled-tubing milling operation to clean out 2,500 ft of formation and perforating debris that plugged the tubing string.
An Analytic Method for Producing Multiarray Induction Logs That Are Free of Dip Effect
Authors: Barber T. D. , Minerbo G. N. 
Published: December 2007

Summary
Dip effect on induction-tool response is a well-documented and well-understood environmental effect that produces increased shoulder effect at moderate dip and a complete scrambling of multiarray induction logs at high dip. Although techniques such as maximum-entropy inversion allow a full correction of the logs, these remain computer-center products that are somewhat time-consuming. Wellsite inversion to correct for dip effect has remained elusive, waiting on more computer power.
In the mid-1960s, Pierre Grimaldi discovered an induction measurement technique that had the remarkable property of returning the same reading in a "thin" bed that it gave in an infinite, homogeneous medium of the same conductivity. The only requirement to satisfy this condition was that the instrument sensors were all in the thin bed. The instrument configuration was such that the voltage measured was a direct solution to Maxwell's equations. Although this was a breakthrough, the instrument configuration was difficult to realize in hardware, particularly with the well-logging technology of the 1960s, and the idea was never published.
The Grimaldi configuration was independently rediscovered in the early 1980s and studied with new modeling codes. It was found that the "remarkable property" of having no shoulder effect was also approximately true at any dip angle. Again, the hardware was deemed to be impractical.
More recently, it was discovered that the array configuration of the AIT* Array Induction Imager family of tools was such that the raw array-measurements data could be processed to be the same as those from a Grimaldi configuration. This led to a real-time algorithm, and a set of Grimaldi curves is now available at the wellsite. This algorithm produces synthetic arrays equivalent to a Grimaldi coil configuration that solve the inverse problem without having to solve Maxwell's equations iteratively.
The Grimaldi configuration is not without its drawbacks— nature is not so kind. The logs have a shallower depth of investigation than those from a conventional induction array of the same spacing. For this reason, the Grimaldi logs supplement, but do not replace, the standard AIT log sets.
An Openhole Memory-Logging System for High-Angle Wells and Bad Hole Conditions
Authors: Elkington P. A. S. , Spencer M. C. , Spratt D. L. 
Published: December 2007

Summary
A mechanism for conveying logging tools inside drillpipe has been developed that reduces the risk and cost of acquiring openhole formation evaluation data in high-angle wells and bad hole conditions. The measurement string is housed inside drillpipe, where it is protected while running in, and pumped into open hole close to final depth. Wireline tools are used for data-quality reasons, but the wireline has been eliminated, giving time, access, and well-control advantages relative to wireline pipe-conveyed logging (PCL). It is an alternative to the formation evaluation element of logging while drilling (FE-LWD), where steering decisions do not rely on real-time petrophysical analysis, particularly when the risk to the bottomhole assembly (BHA) is high. The system's ability to acquire data while conditioning the hole contributes to its efficiency and is advantageous in bad hole conditions.
A 1.4-km horizontal test loop was constructed to help develop and prove the tool deployment and signaling mechanism. Insights gained during this process resulted in the development of novel payload delivery seals—key components in the system.
Formation evaluation data have been acquired in 220 wells; they include horizontal wells for which other logging solutions are unattractive for reasons of accessibility and/or cost. Knowledge gained from the interpretation of these data sets has influenced completions in some wellbores and guided remedial action in others.
Production of Pipeline-Quality Natural Gas With the Molecular Gate CO2 Removal Process
Authors: Wills James , Shemaria Mark , Mitariten Michael J. 
Published: December 2007

Summary
In May 2002, the first Molecular Gate* Carbon Dioxide Removal system for the removal of carbon dioxide and water was started at the Tidelands Oil Production Co. facility in Long Beach, California. The feed source for the unit is hydrocarbon-rich, water-saturated, associated gas from waterflood enhanced-oil-recovery (EOR) operations. The feed CO2 concentration varies widely and is typically more than 30%, while the unit reduces the carbon dioxide level to less than 2%. The unit removes the carbon dioxide, heavy hydrocarbons, and water-producing pipeline specification gas for sale to the local natural gas utility company.
Three-Phase Flow WAG Processes in Mixed-Wet Porous Media: Pore-Scale Network Simulations and Comparison With Water-Wet Micromodel Experiments
Authors: van Dijke M. I. J. , Sorbie K. S. , Sohrabi M. , Danesh A. 
Published: December 2007

SummaryThe pore-scale physics of water-alternating-gas (WAG) injection is still not completely understood. We summarize the development of a 3D pore-scale network simulator for capillary-dominated three-phase flow in media where wettability varies from pore to pore. Reduction of phase continuity has required incorporation of multiple displacements for mobilization of disconnected phase clusters. WAG processes have been simulated, for which saturation paths are recorded along with statistics of phase pore occupancies and displacement mechanisms, showing the importance of multiple displacements. Furthermore, using 2D network simulations, we have modeled the WAG floods following primary drainage and initial waterflooding in a water-wet micromodel. Good qualitative agreement is found, in particular with respect to the displacement mechanisms occurring during the WAG cycles.