bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Laboratory and Field Testing to Identify Potential Production Problems in the Troll Field
Authors: Hartley R. , Jadid M. Bin 
Published: December 2007

Summary
The areal extent of the oil found in Troll made it clear at a very early stage in the field's appraisal that subsea wells would be required if the oil were developed. Owing to cooling in the subsea flowline, subsea wells can be expected to pose more production chemistry problems than would be expected with conventional platform wells. Consequently, a number of laboratory tests were carried out during the appraisal campaign to identify problems to be expected with scaling, foaming, emulsification, wax deposition, and hydrates. Dehydration and wax deposition tests were also carried out offshore during appraisal-well testing. These tests are described, together with the methods subsequently adopted to minimize future production problems.
Beckingham 36 Horizontal Well
Authors: Hardman P. 
Published: December 2007

Summary
BP Petroleum Development Ltd. successfully drilled and completed the first horizontal well in the United Kingdom as part of its 1985 R&D program. The well, Beckingham 36 (BK 36), was drilled on an existing land field near Gainsborough, U.K. This paper discusses the detailed planning for and the execution of the drilling operation. Conclusions and recommendations are presented for future wells.
Water Content of CO2 in Equilibrium With Liquid Water and/or Hydrates
Authors: Song Kyoo Y. , Kobayashi Riki 
Published: December 2007

Summary
Experimentally measured water content in CO2-rich fluid in the gaseous or liquid state in equilibrium with liquid water or hydrate is presented for pressures ranging from 100 to 2,000 psia [0.69 to 13.79 MPa] and temperatures from −19 to 77°F [−28.33 to 25.0°C]. The water content of the CO2-rich phase along the three-phase equilibria, i.e., liquid water/liquid CO2/gas to the three-phase critical endpoint, is also reported. The experimental results from this study on the water content in the CO2-rich phases have been combined with earlier research results of the CO2/water binary system in the hydrate-free region from 77 to 200°F [25.0 to 93.33°C] and pressures to 3,000 psia [20.69 MPa] to produce a comprehensive plot.
The high degree of complexity in the phase behavior of a CO2/water binary system, which exhibits several pairs of equilibrium phases for the conditions, is shown. To make the data more intelligible than they are in their raw form, the data are presented in terms of the pressure enhancement of the water content along isotherms. Finally, the activity coefficients of water in the CO2-rich phases are summarized.
A Simple Buildup Analysis Method To Determine Well Drainage Area and Drawdown Pressure for a Stabilized Well
Authors: Bossie-Codreanu D. 
Published: December 2007

Summary
This paper presents a new method that applies to wells that are shut in after having reached pseudosteady-state flow conditions. Based on the complete Miller-Dyes-Hutchinson (MDH) equation, a corrected pressure is defined that allows extension of the semilog straight line by about two log cycles for symmetric systems and one-half log cycle for others. The drainage area is directly computed. If the final recorded shut-in pressures depart from the straight line, it is also possible to compute the shape factor and the average pressure independently of the initial pressure.
Hydrocarbon Saturation Equation in Shaly Sands According to the S-B Conductivity Model
Authors: Silva Pedro L. , Bassiouni Zaki 
Published: December 2007

Summary
The Silva-Bassiouni (S-B) conductivity model is used to derive a water-saturation equation for hydrocarbon-bearing shaly sands. The performance of the equation is evaluated by comparing calculated and experimental Sw values obtained at 25°C [77°F]. The comparison proved the equation to be valid and accurate.
Several saturation-exponent determination procedures are presented and evaluated. These methods require laboratory core measurements. In the absence of such data, the use of a generalized value of two is supported by statistical analysis.
In its present form, the S-B model can be used in the analysis of laboratory measurements, especially in the determination of the saturation exponent, n, of shaly sands. It is believed that further extension of the S-B model will provide means of saturation determination from log data. This possibility is currently being explored.
Selecting a Perforating System
Authors: King George E. 
Published: December 2007

The purpose of a perforator is to create in the casing a hole that extends into the formation to allow the efficient production or injection of fluids. This entrance hole may be made by any of three methods.

Shaped-Charge Perforating
The most common method of perforating is shaped-charge or "jet" perforating. The shaped charge-an outgrowth of the World War II bazooka-is available in several sizes and types for various perforating applications. It has four principal components (Fig. 1): the outer case, the primer, the powder, and the metal liner. When the charge is fired, the pressure from the exploding powder deforms the metal liner. The shape of the charge, which is dictated by the case and the liner, focuses the energy in a single direction. The pressure and the now-fluid liner form a "jet" that can punch a hole through the casing and into the formation. The time from initiation to completion of the jet is about 0.1 ms and pressures up to 4 million psi [27.6 GPa] drive the tip of the jet at speeds of roughly 30,000 ft/sec [9144 m/s]. The jet penetrates the formation to depths of from about 3 to 18 in. [7.6 to 46 cm], depending on the type and shape of the metal liner, the characteristics of the formation, and, to a lesser extent, the weight of the explosive.
The charges may be held in any of three types of guns: casing guns, expendable guns, and through-tubing guns. The casing gun, which may be run on wireline or conveyed by tubing, is available in diameters from 1 3/8 through 7 in. [3.5 through 17.8 cm]. The charges are contained within the gun (Fig. 2), protected from impact damage and from the well fluids. In the larger guns, they range from 1 to 16 shots/ft [3 to 52 shots/m]; in the smaller guns, from 1 to 4 shots/ft [3 to 13 shots/m]. The charges are aligned by sleeves, rubber pop-up caps, or in metal strip holders in the guns. The positioning is necessary to let the charge penetrate the special thin sections of the guns. Reusable guns use screw ports or port plugs with a center thickness of 0.1 in. [0.254 cm]. This thin section of the port plug is much easier to penetrate than the 0.5- to 0.68-in. [1.27- to 1.727-cm] gun wall thickness. The single-use or "retrievable expendable" scallop guns have the gun body section over the charge locations milled to about 0.1 in. [0.254 cm] thick. The jet punches a hole through the port plug or scallop and into the casing, cement, and formation. The perforation penetration is sharply reduced if the charge is misaligned and shoots through the body of the gun. Casing damage from perforating with even the high-density guns is relatively minimal if the casing is backed up with cement (Fig. 3).
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The Apparent Viscosity of Foams in Homogeneous Bead Packs
Authors: Falls A. H. , Musters J. J. , Ratulowski J. 
Published: December 2007

Summary
The mobilities of aqueous foams of known texture have been measured in homogeneous bead packs. To correlate the data, a theory developed recently to describe the apparent viscosity of foams in smooth capillaries is extended to account for (1) the capillary pressure imposed by the porous medium and (2) constricted flow paths. In porous media, apparent gas viscosity depends strongly on foam-bubble size; for large bubble sizes, it is proportional to the third power of the ratio of the hydraulic radius of the pack to the bubble radius. Foams of uniform texture are pseudoplastic. At low shear rates, the viscosity varies inversely with a capillary number; at higher rates, it depends on the capillary number to the - ⅓ power when the bubble size is large compared with the pore size and on the - ⅔ power of capillary number when the bubble size is smaller.
Top-Drive Drilling System Evaluation
Authors: Cavanaugh James M. , Adams David M. 
Published: December 2007

Summary
Since drilling began, the industry has continuously strived to improve rotating and handling of drillpipe. With these improvements, on-bottom rotating time has been reduced to 25 to 30% of total well time, which has proved acceptable for the U.S. gulf coast. Attention is now being focused on nonrotating time, and with the introduction of the top-drive system, this time can be reduced primarily through pipe handling. Three wells were drilled from a platform in Mustang Island, offshore Texas, and the top-drive drilling system was used and tracked for time savings vs. a typical kelly/rotary system. It has been reported that as much as 20 to 25% time savings can be obtained with the top drive. Definite time savings can be expected with the top-drive drilling system, but the magnitude reported was not experienced on the three wells discussed here. It was established that roughly 6% of drilling cost or 4% of total well cost could be saved with the top drive, which represents 11 % of drilling time or 8% of total well time.
Onboard System Provides Stability, Mooring, and Motion Analysis for Semisubmersible Drilling Operations
Authors: Foreman Russell D. , Beynet P. A. , Singhal S. N. , Seidl L. H. 
Published: December 2007

Summary
Vessel stability, mooring, and motion-related decisions on semisubmersible drillships have historically been made with a combination of the marine crew's experience and guidelines documented in the ship's operating manual. This is especially true once the vessel is on location and operations are under way. This situation leaves the operator dependent on contractors to anticipate problems and to take correct remedial action.
This paper presents a computer system that combines state-of-the-art marine technology with a simple user interface to provide information useful to operations personnel in making decisions. The purpose of the system is not to take over any of the contractors' responsibilities. It does provide additional information useful in making marine-related decisions. This allows the contractor and the operator to combine experience and analysis and work toward a mutual decision.
This tool, referred to as the "Onboard System," was used by drilling personnel on two semisubmersibles in the Bering Sea. In addition to stability, mooring, and motion capabilities, the Onboard System provides a data base of environmental information and corresponding vessel responses while on location.
Operational Aspects of Extended High-Pressure Well Tests from a Floater
Authors: Roberts E. W. 
Published: December 2007

Summary
During Summer 1985, an extended high-pressure gas-condensate well test was conducted from a semisubmersible drilling unit in Block 29/5a. This paper is a case history discussing the planning and implementation of the production-test operation.
The Well 29/5a-3 production test is believed to have been the most extensive high-pressure test conducted in the U.K. North Sea from a floating drilling unit. In the past, because of equipment and/or environmental constraints, high-pressure testing has been limited to short flow and buildup periods. Also, the majority of "expected" high-pressure tests conducted with 15,000-psi [103-MPa] equipment either have rapidly depleted (high-pressure, low-volume zone) or have been terminated prematurely because of mechanical problems. In contrast, the Well 29/5a-3 production test experienced no major equipment failures. In addition, surface pressure readout gauges were successfully installed under extreme pressure and temperature conditions.
Proper operational planning and equipment selection proved vital in implementing the production test and achieving the main objectives.
Evaluating Drilling Practice in Deviated Wells With Torque and Weight Data
Authors: Lesage M. , Falconer I. G. , Wick C. J. 
Published: December 2007

SummaryThis paper shows how to estimate two friction coefficients on a foot-by-foot basis at the wellsite with both measurement-while-drilling (MWD) and surface values of weight on bit (WOB) and torque. A log of the coefficients with depth can be used to diagnose drilling problems in directional wells. Field examples are given that show how the technique detects incipient sticking and hanging stabilizers. Data are also used to evaluate the time spent on wiper trips and in circulating before making connections.
Prediction of Wellbore Trajectory Considering Bottomhole Assembly and Drill-Bit Dynamics
Authors: Brakel J. D. , Azar J. J. 
Published: December 2007

Summary
This paper presents a numerical dynamic model to predict wellbore trajectory in both the vertical and horizontal planes. The model is three-dimensional (3D) and consists of the idealization of the bottomhole assembly (BHA) into a number of finite elements. Inertia properties are included to predict the transient dynamic behavior of the assembly during drilling. To ensure the correct boundary condition at the bit/rock interface, two rock/bit interaction models, one for a roller-cone bit and one for a polycrystalline-diamond-compact (PDC) bit, are developed. The time average of the rock/bit interaction force components is used to obtain an indication about the directional tendencies of the BHA. Examples of the rock/bit interaction forces for roller-cone and PDC bits and examples of the motion of a holding assembly for both bit types are given. The effects of hole inclination, weight on bit (WOB), rotary speed, and bit/stabilizer clearance are presented for an example of a building, holding, and dropping assembly. The deviation tendencies, as predicted by the model for several building and holding assemblies, are compared with field case data.
The Effect of Vertical Fractures on Well Productivity
Authors: McGuire W.J. , Sikora V.J. 
Published: December 2007

Introduction
Several years ago, we used an electric analogue computer to study the effect of vertical fractures on the productivity of wells in expanding fluid-drive reservoirs. The results of this work were used both as a guide to research and as a basis for the design of actual fracturing operations. In 1958, Dyes, Kemp and Caudle published portions of the data from this study. The results were released in 1959 to service companies for use in fracturing guides.
The purpose of this note is to discuss the experimental conditions and assumptions which were made to derive the information which is already partially a matter of public record.

Assumptions
This study applies to fractures which extend in a vertical plane symmetrically from the well. For simplicity, we chose to study the case of a well in a square drainage area with its fractures extending toward two of its nearest neighbors. We have assumed no migration of fluid across the boundary of this area. The quadrant shown in Fig. 1 models this system.
We made the usual assumptions that the reservoir is homogeneous and isotropic, that the fluid is homogeneous and that production is effected by fluid-expansion drive. We also assumed that the fracture extends from top to bottom of the reservoir.
Of more practical interest is our assumption that the fracture does not change the size of the drainage area. This premise is appropriate if all the wells in the reservoir are fractured in the same way. But where a single well is fractured, its drainage area may be enlarged at the expense of its neighbors. This could be of economic importance. The assumption that the fracture will not extend beyond the established drainage area of the well also limits the application of the results. Such long fractures will yield benefits in excess of those predicted here.
When we assume homogeneity, we disregard the frequently observed zone of damage in the vicinity of the well. Where damage is severe, the benefits resulting from by-passing it will far exceed those predicted by this study. All comparisons were made of systems producing in the semi-steady state. By this we mean that equal volumes contributed equally to flow (pressure was dropping at a uniform rate throughout the system) when the rate of flow was observed.
Safe Purging of Natural Gas Pipelines
Authors: Perkins T. K. , Euchner J. A. 
Published: December 2007

Summary
When a newly constructed natural gas pipeline is put into service, it can be safely purged of air by injection of a slug of inert gas, such as N2. The method of sizing the required slug is based on a model of dispersion in turbulent flow in conjunction with flammability limits.
Analysis of Electric-Submersible-Pumping Systems
Authors: Nolen K. B. , Glbbs S. G. 
Published: December 2007

Summary
This paper presents a field-proven analytical method of evaluating electric-submersible-pumping equipment and well performance jointly. A computerized mathematical model that considers the effects of free gas, pump speed (variable-frequency drives), and pump tapering is described. The method allows accurate calculations of important downhole parameters, including pump intake pressure, pump intake volume (including free gas), pump pressure, and fluid density profile. Lifting cost parameters—such as pump and motor power requirements, monthly power consumption, pump and motor performance, and overall system efficiency—are also determined. Once operating conditions are known, decisions can be made on ways to increase production (if additional potential exists) or to reduce operating costs. Thus, the same basic goals that often justify frequent analysis of rod-pumping systems can be applied to submersible pumping.
Porous-Media Momentum Equation for Highly Accelerated Flow
Authors: Blick E. F. , Civan F. 
Published: December 2007

Summary
A new porous-media momentum (capillary-orifice model) equation has been developed to account for unsteady flow through porous media. The equation contains not only the familiar permeability and non-Darcy factor terms but also momentum flux and acceleration terms. An analysis of the order of magnitude of these terms indicates when they are important.
Thermodynamic Analysis of Transient Two-Phase Flow in Petroleum Reservoirs
Authors: Tlab Djebbar , Duruewuru Anthony U. 
Published: December 2007

Summary
This paper presents a new method of analyzing the performance of a flowing well. The method uses a thermodynamic property known as the "availability function." The advantage of the availability-function method of analysis is that it allows the calculation of the thermodynamic efficiency of all processes, including not only those that are large work producers or consumers but also those that do not have work production or consumption as their goal. The efficiency of a process indicates how closely the process reaches its ultimate performance. It can be used as a tool to compare various processes and to make a sound decision on where improvements are possible.
The model developed in this study is capable of handling a single-component, single-phase or two-phase flow. The fluid-flow equations provide the thermodynamic properties—energy, enthalpy, entropy, and the fluid velocity—for use in the calculations of the theoretical maximum reversible work, the useful energy used to lift the hydrocarbon fluid from the bottom of the well to the surface, and the energy lost because of irreversibilities.
Results obtained from this study show that (1) a considerable fraction of the fluid energy is lost because of irreversibilities, especially at the early stages of production, and (2) the thermodynamic efficiency of fluid production would be greatly improved by minimizing wellbore heat loss.
Characterization and Control of Formation Damage During Waterflooding of a High-Clay-Content Reservoir
Authors: Leone Joseph A. , Scott E. Mark 
Published: December 2007

Summary
Permeability damage was suspected as a factor contributing to postcompletion production declines observed during waterflooding of a friable to unconsolidated sandstone. A loss in water injectivity also indicated that near-wellbore damage may have been occurring. This paper summarizes the laboratory studies undertaken to evaluate and understand permeability damage in this formation. The experimental program consisted of primarily coreflooding experiments to evaluate the influence of injection fluid composition, temperature, mineralogy, and flow velocity on permeability damage. The significance of damage during brine injection was observed to be a strong function of mineralogy and injection rate. Permeability losses of &gt; 60% were observed in cores from some sand intervals, while little or no damage was apparent in cores from a second zone in identical wells. In the sands that were susceptible to brine damage, a critical velocity below which permeability damage did not occur was repeatedly established. The occurrence of a critical velocity, along with other observations, indicated that the primary damage mechanism was fines migration. Damage could be controlled by maintaining velocities below the critical value or reducing the pH of the injected brine.
Settling Velocity of Variously Shaped Particles in Drilling and Fracturing Fluids
Authors: Peden James M. , Luo Yuejin 
Published: December 2007

SummaryThe settling velocities of a variety of shaped particles to simulate drilled cuttings were measured in both Newtonian and non-Newtonian fluids. The results showed that the particle drag coefficient is a function of the particle Reynolds number and, in the case of power-law-model fluids, of the flow behavior index. A new generalized model has been developed for predicting the settling velocities of particles of various shapes in both Newtonian and power-law fluids over a range of flow regimes.
Thermal Cracking of Heavy-Oil/ Mineral Matrix Systems
Authors: Monin J. C. , Audibert A. 
Published: December 2007

Summary
At temperatures and pressures encountered during thermal recovery, chemical reactions involving oil, possibly water, and mineral matrix may lead to significant changes in composition of the phases. This work focuses on thermal alteration of four crude oils with different geochemical compositions. The tests were performed in an autoclave at 350°C [660°F] for 200 hours. The oil was in the presence of water and a mineral matrix representative of reservoir rocks.
The formation of significant amounts of insoluble organic material was observed in all tests. Gaseous hydrocarbons (mainly methane) formed by pyrolysis. CO2 evolution depended on oil and matrix compositions; moreover, water was found to be a reactant in the formation of oxygen-containing components.
For crude oils investigated, the oil phase was significantly enriched in lighter hydrocarbons (mainly in saturates). However, aromatic content was less affected by the thermal treatment. On the other hand, asphaltenes and, to a lesser extent, resins were the main precursors of insoluble material. These results provide new insight on mechanisms of the cracking reactions involved in thermal recovery processes.