bluuebunny/crossref_metadata_2025_split huggingface dataset:
Whipstock Casing Installation Advances Well Construction Process
Authors: Mayfield David , Rodriguez Edgar M. , Nordenstam Erik , Buster Jerry 
Published: December 2007

Abstract
A technological breakthrough in the well construction process was recently accomplished in the deepwater Gulf of Mexico. An 11-3/4" O.D. liner was successfully installed through a whipstock window cut into a 13-5/8" casing. It was the first documented attempt worldwide to run casing larger than 10-3/4" O.D. through a 13-5/8" window.
The job's success can be attributed to thorough planning of well site operations and computer modeling of the proposed installation. The primary components of the planning activity included 1) analysis of available casing exit systems, 2) modeling of the bending and compressive loading on the 11-3/4" liner connections, and 3) detailed modeling of the drag expected during liner running operations both through the whipstock and into the deviated hole to total depth.
Mechanisms Of Mineral Scale Inhibition
Authors: Tomson M. B. , Fu G. , Watson M. A. , Kan A. T. 
Published: December 2007

Abstract
The adsorption and desorption potential of inhibitors to crystal nuclei has never been determined at the extremely low, threshold levels that are known to inhibit nucleation. An extensive study of adsorption and desorption isotherms of four phosphonates on barite or calcite are tested over a wide range of solution conditions (0 – 1 M NaCl, 0 – 0.1 M Ca, 0 – 0.33 M sulfate, 4.6–6.4 pH). From these adsorption/desorption observations, it is proposed that the primary driving force for adsorption is related to simple hydrophobic repulsion from solution of a macro neutral molecule and not, as is generally presumed some specific inhibitor-surface interaction. A single isotherm may be derived from these vastly different adsorbent, adsorbate combinations after the solid phase concentration is normalized to per unit surface area and the solution phase concentration is normalized to the concentration of metal phosphonate concentrations. From the nucleation study, it is observed that the inhibitor needed to completely inhibit barite formation is approximately equal to 16% surface coverage. Equation to predict minimum inhibitor need is proposed based upon this model and compared with field observations. Brine chemistry of a specific well dictates the solution speciation of scale inhibitors and adsorption potential, thereby, that will determine the efficiency of inhibitor. Surprisingly, the range of predicted inhibitor concentrations is quite similar to what is observed in the field as a minimum effective dose, even though it was arrived at by a completely independent method of calculation.
A Surface Sensitive Study of the Influence of Corrosion Inhibitor on Chemical Scale Inhibition
Authors: Wylde Jonathan J. , Allen Geoffrey C. , Collins Ian R. 
Published: December 2007

Abstract
A combination of Laser Raman Spectroscopy, Secondary Ion Mass Spectrometry and Scanning Electron Microscopy has been used to investigate the influence of corrosion inhibitors on the mechanism of scale formation.
In a series of experiments mixed barium and strontium sulphate scales were precipitated onto a steel surface in the separate presence of three generically different scale inhibitors. In each, one of two contemporary corrosion inhibitors was also added and the rate of scale growth monitored. All experiments were performed at a constant temperature, pressure and solution pH of 25°C, 1 ATM and 4.5 respectively.
A significant influence on the rate of scale formation was observed in the presence of corrosion inhibitors. The corrosion inhibitors affected the way in which scale ions, as well as scale inhibitors, attached themselves to the surface. These data indicate the presence of subtle interactions in these multi-component systems which strongly influence the efficiency of individual production chemicals.
Friction Factors for Turbulent Flow of Non-Newtonian Fluids in Coiled Tubing
Authors: Rao Bharath N. 
Published: December 2007

Abstract
The applicability of Newtonian friction factor correlations for predicting friction pressure losses in turbulent coiled tubing (CT) flow of non-Newtonian fluids is investigated. All correlations presented are expressed in a simple and convenient form by separating the contribution of curvature effects of the reel and friction pressure losses in corresponding straight tubing. The primary advantage of separating reel effects from the straight tubing pressure losses is that the form of the friction factor correlation provides more generality and can be extended to both Newtonian and non-Newtonian fluids. Moreover, pipe roughness effects can be easily incorporated if necessary, and a single correlation can be used to predict friction pressure losses in both straight and reeled tubing. The correlations presented are valid for a wide range of generalized Reynolds numbers, and are applicable to most combinations of reel and tubing sizes available today. The results obtained from these proposed correlations are compared with published experimental data and very good agreement is obtained.
Regional Data Analysis to Better Predict Drilling Success: Brushy Canyon Formation, Delaware Basin, New Mexico
Authors: Balch R. S. , Hart D. M. , Weiss W. W. , Broadhead R. F. 
Published: December 2007

AbstractIncomplete or sparse information introduces a high level of risk for oil exploration and development projects. "Expert" systems developed and used in several disciplines and industries have demonstrated beneficial results in modeling the decision making process of knowledgeable experts. A state-of-the-art exploration "expert" tool using a computerized data base and computer maps generated by neural networks, is being developed using fuzzy logic, a relatively new mathematical treatment of imprecise or non-explicit parameters.Analysis to date includes generation of regional scale maps of aeromagnetic, gravity, structure, thickness, and production data for the target Brushy Canyon Formation in the Delaware Basin, New Mexico. For each regional scale map, data attributes were also computed to look for more subtle trends. These attributes include directional first and second derivatives, dip azimuth and magnitude, and azimuth and magnitude of curvature. These data were mapped and gridded to a 40 acre spacing, the current well spacing for Delaware pools in New Mexico, and compared to average monthly production in the first year for Delaware Brushy Canyon wells. The geophysical and geologic data covers 60478 bins (3780 square miles), of which 2434 of these bins have oil, gas and water production data. Using a new fuzzy ranking tool each data attribute was ranked for its ability to predict production potential at these well locations. The highest ranked attributes are gravity dip-azimuth, second latitude derivative of thickness, longitude derivative of gravity, and longitude derivative of structure. These attributes are being used to generate a production potential map for the Delaware basin, using neural networks and expert systems, at the scale of 40 acres. Such a map would be a useful tool for evaluating the potential of infill, step out, and wildcat wells in the Delaware basin, both at reservoir and regional scales.
Applicability of Timely Gas Injection in Gas Condensate Fields To Improve Well Productivity
Authors: Marokane D. , Logmo-Ngog A. B. , Sarkar R. 
Published: December 2007

Abstract
Gas-condensate reservoirs suffer losses in well productivity due to near wellbore condensate dropout when the flowing bottomhole pressure declines below the dew point pressure. To alleviate the problem, pressure maintenance and gas cycling are common practices for developing gas condensate reservoirs.
A study has been conducted to investigate the applicability of one-time produced gas injection in removing the condensate bank around the wellbore and thereby restoring well productivity. The study focused on two major issues: the optimum time of commencing gas injection and the optimum volume that will remove the condensate bank permanently and restore well productivity. The practice will accelerate the production rate per well and maximize the ultimate hydrocarbon recovery.
Three gas-condensate fluid samples with maximum liquid dropout in the range of 6 %, 11 %, and 21 % were used. The benefit of the method was investigated using a full-field compositional reservoir simulation model of a gas condensate field.
Reservoir simulation results indicated that, for the lean gases, the best time of starting the gas injection was when the average reservoir pressure around the producing well fell below the maximum liquid dropout pressures. For the rich gas, however, gas injection starting at average reservoir pressure above the maximum liquid dropout pressure resulted in better recovery.
The study showed that one-time gas injection not only restored the well productivity and increased reserves but also accelerated the recovery process. These findings bring a different perspective to the development and management of gas condensate reservoirs.
A Natural Polymer-Based Crosslinker System for Conformance Gel Systems
Authors: Reddy B. R. , Eoff Larry , Dalrymple E. Dwyann , Black Kathy , Brown David , Rietjens Marcel 
Published: December 2007

AbstractThis paper describes a material derived from natural sources that can be used to crosslink a variety of polymers over a broad temperature range to produce gels for conformance applications.Delayed crosslinked polymer systems have been used for many years in conformance applications. For the past decade, the most widely used system has been based on chromium (+3) crosslinked polyacrylamide. Organic crosslinkers, such as phenol/formaldehyde and polyethyleneimine (PEI) have also been used with a variety of polymers. However, these systems are being scrutinized by governmental agencies and have been scheduled for phase-out in some countries. Because of these issues, a single, environmentally friendly crosslinker that could be used with a variety of polymers over a broad temperature range was the focus of this study.This paper details the laboratory development of an environmentally friendly, natural polyamine crosslinker system. This crosslinker can be used with a variety of polymers, such as polyacrylamide, AMPS/acrylamide, or alkylacrylate polymers. Gels ranging from stiff and ringing type to "lipping" gels have been obtained. The data illustrate a simple, commercially available system that can be applied to field operations. Potential crosslinking mechanism(s) of the system will be discussed.
Three-Phase Flow in Wag Processes in Mixed-Wet Porous Media: Pore-Scale Network Simulations and Comparison with Micromodel Experiments
Authors: van Dijke M. I. J. , Sorbie K. S. , Sohrabi M. , Tehrani D. , Danesh A. 
Published: December 2007

AbstractWater-alternating-gas (WAG) injection is a technique which has been applied successfully in the field for improving oil recovery. However, there is still an incomplete understanding of the pore-scale physics of WAG processes and how these lead to improved oil recovery. This is especially true in systems of non-uniform wettability e.g. mixed-wet rocks. In this paper, we describe the development of a pore-scale network simulator for capillary-dominated three-phase flow in media where the wettability varies from pore to pore. Reduction of phase continuity in weakly wetted pores has required incorporation of double and multiple displacements for mobilisation of disconnected phase clusters. Three-phase flow processes, in particular WAG injection cycles, have been simulated for which the saturation paths are recorded along with the statistics of the corresponding phase pore occupancies and displacement mechanisms. Comparison of the saturation paths obtained in 3-D mixed-wet network simulations shows reasonable agreement with paths for an analytical model, despite the imposed low phase continuity. The WAG cycle simulations show the importance of multiple displacements during higher order WAG floods. Furthermore, using 2-D network simulations we have modelled the WAG floods following primary drainage and initial water flooding in a water-wet micromodel. Good agreement is found between simulation and experiment, in particular with respect to the displacement mechanisms occurring during the WAG cycles.
Three-Phase Hydraulic Conductances in Angular Capillaries
Authors: Al-Futaisi Ahmed , Patzek Tad W. 
Published: December 2007

AbstractIn this paper, we extend to three fluid phases a prior finite-element study of hydraulic conductance of two-phase creeping flow in angular capillaries. Previously, we obtained analytic expressions for the hydraulic conductance of water in corner filaments. Here we present the results of a large numerical study with a high-resolution finite element method that solves the three-phase creeping flow approximation of the Navier-Stokes equation. Using the projection-pursuit regression approach, we provide simple analytic expressions for the hydraulic conductance of an intermediate layer of oil sandwiched between water in the corners of the capillary and gas in the center. Our correlations are derived for the oil layers bounded by the concave or convex interfaces that are rigid or allow perfect slip. Therefore, our correlations are applicable to drainage, spontaneous imbibition, and forced imbibition with maximum feasible hysteresis of each contact angle, oil/water and gas/oil. These correlations should be useful in porenetwork calculations of three-phase relative permeabilities of spreading oils. Finally, we compare our results with the existing correlations by Zhou et al., and Hui & Blunt, who assumed thin-film flow with an effective film thickness proportional to the ratio of the average, our correlations are two-four times closer to the numerical results than the corresponding correlations by Zhou et al., and Hui & Blunt.
Geochemical Modeling of Fracture Filling
Authors: Noh Myeong H. , Lake Larry W. 
Published: December 2007

Abstract
This paper reports on a mathematical model to simulate hydrodynamics and fluid-mineral reactions in the fracture within a permeable media. Fluid convection, diffusion and precipitation / dissolution (PD) reaction inside a finite space are solved as a simplified representation of natural fracture mineralization. The problem involves mass transfer within the fluid accompanied by chemical reaction at the fracture surface. Mass-conservation equations for components in the fluid are solved in this problem, and these are coupled with chemical reaction at the fracture surface. The intent of this model is to show the time evolution of fracture aperture shrinkage patterns caused by PD reactions. We present the aperture distribution along the fracture with various boundary conditions. Partially cemented fractures are created if cementation fails to completely fill the fracture or if subsequent dissolution leaches out some of the mineral.
Stimulation of a Deep Sour Gas Reservoir using Gelled Acid
Authors: Nasr-El-Din H. A. , Al-Mutairi S. H. , Al-Jari M. , Metcalf A. S. , Walters W. 
Published: December 2007

Abstract
Stimulation should always begin with a good understanding of the well history and the reservoir rock. This should include an evaluation of the formation composition and flow characteristics, permeability and porosity, and the mechanical properties of the rock. Determination of the "Key Factors" limiting stimulation success should be identified. The potential treatment fluids and technique should be evaluated for the ability to provide the necessary benefits to overcome these limits.
This paper describes stimulation design and results in a carbonate gas field located in eastern Saudi Arabia. The field produces gas with H2S that varies from 0 to 10 vol%. The Khuff reservoirs, at 11,000 to 12,000 ft, are highly acid soluble carbonates (&gt; 85 wt%) with elevated bottom hole temperatures approaching 275°F and a composition having increasing dolomitization with increasing depth. Acid leak-off control problems result from the presence of natural fractures in the formation. Various retarded acid systems were tested with reservoir rocks. In addition, the issues of corrosion control were considered given the low-carbon steel tubulars downhole (L-80 & C-95) and the H2S. Although the gas is sour, proper design of acid systems eliminates problems of iron sulfide and elemental sulfur precipitation.
Evaluation of cored material showed 15 wt% anhydrite streaks. Kinetics studies conducted using reservoir rock indicated that the reaction rate of the in-situ gelled acid is an order of magnitude lower than that of neat acid. An acceptable corrosion rate on all metals by the acid in the presence of H2S and compatibility of all systems with reservoir fluids were obtained. Wells have been treated using acid fracturing techniques employing viscous fluids without encountering any operational problems. Substantial increases in gas production and flowing wellhead pressures have resulted from these treatments. Analysis of well flow back samples collected following acid fracture treatments was used to assess the effectiveness of the fracture treatments.
Field Application of Glass Bubbles as a Density Reducing Agent in an Oil Base Drilling Fluid for Marginal/Low-Permeability/Low-Pressure Reservoirs
Authors: Blanco J. , Ramirez F. , Mata F. , Ojeda A. , Atencio B. 
Published: December 2007

Abstract
This paper shows the results of a successful application of the addition of hollow glass spheres, also known as glass bubbles, as a density reducing agent in a drilling fluid. In this field application, glass bubbles were used in combination with an oil based drilling fluid (Core-Drill-N). It was corroborated that the fluid-glass bubble mix is stable, homogeneous, and is compatible with conventional mud motors, bits and surface cleaning equipment.. The system has good rheological and filtration control properties and is suitable for drilling low pressure reservoirs, low permeability and pay zones.
During this field application in the well MOT-25B in Venezuela, the density of the base fluid was maintained between 7.1-7.3 ppg (near balance condition) with calcium carbonate as bridging agent.
This technology is an alternative to the use of aerated fluids where the reservoir requires a fluid density between 6.0-7.5 ppg, offering some economical and technical advantages due to the elimination of surface compressing and air injection facilities, and to the simplification of operations required to avoid excessive overbalance during drillpipe trips. Additional potential benefits of this low-density fluid include torque reduction as a result of higher lubricity, higher penetration rates and decreased formation damage due to lower invasion of drilling fluid. Glass bubbles are also an alternative to decrease the density of water based drilling fluids, polymer-based fluids, emulsion systems and brines.
Laboratory tests were also carried out with different concentrations of glass bubbles in order to evaluate potential field substitutes for aerated fluids in wells which might require lower density fluids. Several formulations for the systems mentioned above were developed with the purpose of achieving maximum density reduction without affecting some mud properties. Fluid density as low as 6.0 ppg was obtained from a 100% oil base mud.
Designed Simulation for a Detailed 3D Turbidite Reservoir Model
Authors: Wang Feng , White Christopher D. 
Published: December 2007

AbstractIntelligent reservoir management requires assessment of risks caused by geologic heterogeneity and examination of alternative development schemes. Numerical simulation is a powerful tool for integrating geologic and development models, but simulation is often too expensive or time-consuming if there are many sensitivities and scenarios to examine. In this paper, response surface methods are used to approximate the relationship between gas recovery responses and reservoir and production parameters. The response models are based on a set of numerical simulations selected using experimental design, which efficiently estimates effects of many factors across a broad range of uncertainty. The three-dimensional reservoir model examined in this study is from an outcrop study of the Permian-age Bell Canyon, which is interpreted as a channel-levee-lobe turbidite system.Examination of realistic reservoir models is complicated by the large number of factors and by correlations between model factors. Principal component analysis can simplify the modeling process by using the correlations to reduce the dimensionality of the factor space. A large number of reservoir geologic parameters are reduced to a small set of principal components while most of the original geological information is still preserved. The principal component design also spans the scatter-cloud of correlated reservoir factors more efficiently. Based on these principal components and several engineering factors, reservoir simulations are selected using a central composite design. Response surface models relating the simulation responses and the design factors are estimated via linear regression. The validity of the models is verified by reservoir simulation of randomly selected points within the feasible region of geological parameters. Uncertainty analysis, including parameter sensitivity estimation and recovery uncertainty assessment, is done conveniently and inexpensively using response surface models and Monte-Carlo simulations. Quality maps identify optimal well locations within the complex depositional setting documented at Willow Mountain.
Successful Acid Treatments in Horizontal Openholes using Dynamic Diversion and Instant Response Downhole Mixing—An In-Depth Postjob Evaluation
Authors: Surjaatmadja Jim B. , McDaniel B. W. , Cheng Alick , Rispler Keith , Rees Matthew J. , Khallad Abe 
Published: December 2007

AbstractThis paper discusses a relatively new acid-stimulation process that uses dynamic fluid energy to divert flow into a specific fracture point in the well that can initiate and accurately place a hydraulic fracture. These acid-stimulation methods often use two independent fluid streams: the acid phase down the treating string and other liquids or gases down the annulus. The annular fluid may simply serve as a wellbore pressurizing component, or with this process, two different fluids can be mixed downhole with high energy to form a homogenous mixture.Using variations of this process, treatments were performed in four openhole, horizontal wells in the same formation. The first well was acid-fractured with coiled tubing to place many small fractures along the open hole. The second well was acidfractured with coiled tubing, but downhole mixing concepts were also used to provide in-situ generation of CO2 foam where fewer, but larger, fractures were placed in this well. The third and fourth wells were treated with acid using blasting-type rotating or non-rotating jetting tools while mixing the acid with CO2 downhole. Numerous small, near-wellbore fractures were the expected result in these two wells.Experimental laboratory investigation of the physical mechanisms that contributed to these successful stimulations was considered important. Large-scale laboratory tests were performed to more closely examine the physical rock response to the jetting mechanism and conditions. The findings of these tests are presented in this paper.
Evaluating Operation Strategies via Integrated Asset Modeling
Authors: Liao Tony Tianlu , Stein Michael H. 
Published: December 2007

Abstract
An integrated asset modeling approach was used to evaluate gas compression and operating strategies for six gas fields in offshore Trinidad. Material balance and well models were linked to a pipeline network model. These IAM models were successfully used to evaluate the benefits of compression and looping of a pipeline segment. The modeling allowed the impact of interference of fields, different sand units within a field, wells, and facility constraints to be quantified. Compression could increase the gas recovery from six Trinidad fields by between 8.8% and 11.7 % of the original gas in place.