bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Implementation of a UNIX Based Distributed Computing System
Authors: Love J. Stanley , Mickael Medhat W.
Published: December 2007

We have designed, implemented, and are running a corporate-wide distributed processing batch queue on a large number of networked workstations using the UNIX® operating system. Atlas Wireline researchers and scientists have used the system for over a year. The large increase in available computer power has greatly reduced the time required for nuclear and electromagnetic tool modeling. Use of remote distributed computing has simultaneously reduced computation costs and increased usable computer time.

The system integrates equipment from different manufacturers, using various CPU architectures, distinct operating system revisions, and even multiple processors per machine. Various differences between the machines have to be accounted for in the master scheduler. These differences include shells, command sets, swap spaces, memory sizes, CPU sizes, and OS revision levels. Remote processing across a network must be performed in a manner that is seamless from the users' perspective. The system currently uses IBM RISC Syst em/6000®, SPARCstation™, HP9000s700, HP9000s800, and DEC Alpha AXP™ machines.

Each CPU in the network has its own speed rating, allowed working hours, and workload parameters. The system is designed so that all of the computers in the network can be optimally scheduled without adversely impacting the primary users of the machines.

The increase in the total usable computational capacity by means of distributed batch computing can change corporate computing strategy. The integration of disparate computer platforms eliminates the need to buy one type of computer for computations, another for graphics, and yet another for day-to-day operations. It might be possible, for example, to meet all research and engineering computing needs with existing networked computers. It may, on the other hand, be advantageous to buy more powerful computers than required for a particular application, so that extra capacity can be applied to other problems by means of the batch scheduler.
A Major Step in Ultra Slimhole Drilling
Authors: Sagot A. M. , Dupuis D. C.
Published: December 2007

In early 1993, two ultraslim hole wells (3" and 3 3/8") were drilled in the Paris Basin of France. Our intention was to quantify the "concepts" associated with new and re-emerging techno-logy. This paper details the drilling performances and the technical aspect of the drilling operations. The paper also presents the tests results of new slim hole drill pipe while performing destructive drilling and wire line coring. The validation of a mud pressure model is also presented. These experiments have confirmed the benefits of slim hole technology and highlighted the need for a dedicated surface equipment to comply with the environmental criteria. Additionally, all the required geological data concerning formations and reservoir fluids were acquired.
Hybrid Coiled Tubing/Snubbing Drilling and Completion System
Authors: Newman K. R. , Doremus D. M.
Published: December 2007

A drilling and completion system has been developed which will handle both continuous pipe (coiled tubing) and jointed pipe. The coiled tubing is handled using a conventional coiled tubing unit. The jointed pipe is handled using a set of snubbing jacks. This paper describes the design considerations and resulting system that was developed. A case history of the first use of this system is also presented.
Acoustic Gas Kick Detection With Wellhead Sonar
Authors: Bang Jon , Mjaaland Svein , Solstad Arne , Hendriks Peter , Jensen L. K.
Published: December 2007

An acoustic gas kick detection system has been successfully tested in full-scale experiments. The principle of operation is similar to that of an echo-sounder system. The method is neither dependent on mud circulation, nor does it require the presence of the drillpipe. It can be applied to both platforms and floating rigs. Furthermore, only surface equipment is required for its operation. In the experiments 150 to 600 1 of gas was injected at a depth of 1210 m both in water and in water-based drilling fluid. The results show that the changes caused by the presence of free gas in the well are easily and instantly detected.
Near-Bit Propagation Resistivity for Reservoir Navigation
Authors: Meyer W. H. , Wu Jian-Qun , Macune D. T. , Harvey P. R.
Published: December 2007

A new propagation resistivity tool has been designed and built with a measure point only 15 feet from the bit. Measurements of near-bit inclination and gamma ray are also provided. All of these measurements are in a package that includes a mud motor. The primary purpose of this tool is to provide a means for staying in a target formation during horizontal drilling. The propagation resistivity measurement of this reservoir navigation tool has the ability to see radially much deeper than focused resistivity devices. The radial direction is the direction of interest in horizontal drilling because the distance between adjacent beds is in the radial direction (relative to the tool). Devices which attempt to see beyond the end of the bit have limitations in a horizontal environment because the distance to the adjacent bed is very large in the direction of the borehole. In addition to the standard 2 MHz frequency, this new propagation resistivity tool has a second frequency of 400 kHz which has a much greater depth of investigation than the 2 MHz frequency. Measuring amplitude and phase at both frequencies produces 4 different depths of investigation at the same measure point. Modeling has shown that adjacent conductive beds can be detected as much as 12 feet away with the 2 MHz frequency and about 32 feet away at the lower frequency. These detection distances refer to the true vertical distance from the borehole to the adjacent bed, but the borehole may not intersect this bed for several hundred feet in horizontal drilling because the borehole is nearly parallel to the bed boundary. In addition, new state-of-the-art electronics and the use of a second transmitter have greatly improved the precision of the resistivity measurements. The result of these improvements is better accuracy in highly resistive formations. Therefore, this tool is able to provide both geosteering and a propagation resistivity measurement as accurate as the best wireline induction tools.
Quality Management Alliance Eliminates Plug Failures
Authors: Heathman James , Carpenter Robert , Marcel Ken , Rimer Charles , Badalamenti Anthony
Published: December 2007

Plug cementing is a very broad term that may include setting cement plugs for abandonment, sidetracking a wellbore, lost-circulation control, or remedial work. There are several means by which this may be accom- plished, including the balanced plug and dump bailer methods. Unfortunately, plug cementing is a process that often receives simplistic treatment. However, even plug cementing is by no means simplistic and can be very costly if not properly executed. In addition to the immediate rig time and materials cost associated with a poor cement plug, there are also potential costs from well control and environmental problems.

This paper describes the activities and results of an operator/service company quality alliance. The immedi- ate project goal was to improve the success rate of cement sidetrack plugs in the US Gulf Coast operating area. All aspects of the cementing process, including slurry design, material and job quality control, and displacement practices were systematically evaluated and modified as necessary. During the latter stages of the project, a recommended plug procedure (RPP) was established that addressed many of the shortcomings of past practices. A continuous job evaluation process or "Quality Management System" was also implemented to ensure continuous monitoring and refinement of the RPP.

Before this procedure was implemented, the prevailing standard in the Gulf Coast was approximately two to five attempts to achieve a successful sidetrack plug. The industry average was approximately 2.4 attempts per kickoff. As of this writing, proper use of the RPP outlined by the study group has achieved a near 100% success rate. Although originally targeted for the Gulf Coast operating area, the RPP has proven to be a global success. This program has provided a multi-million dollar cost reduction to the operating companies using it, and illustrates the value of properly structured operator/service company technology alliances.
Experimental Evaluations of Drill Bit and Drill String Dynamics
Authors: Dykstra M. W. , Chen D. C.-K. , Warren T. M. , Zannoni S. A.
Published: December 2007

Laboratory and field experiments were performed to investigate the dynamics of the drill bit and drill string. Laboratory results for Anti-whirl and conventional polycrystalline diamond compact (PDC) bits showed that vibrations of the former were an order of magnitude less than those of the latter. Backward whirl of the conventional PDC bit was prevalent in both hard and soft formations. Roller cone bit tests suggested that they too were subject to backward whirl, and the lateral vibrations that resulted were an order of magnitude worse than the axial vibrations commonly associated with these bits.

Field tests were performed using a single drill string design with the conventional PDC and roller cone bit. Simultaneous surface and downhole measurements were made. Results suggested that bit vibration amplitudes rapidly diminished with distance from the bit, and that stabilizers had a significant isolating effect. Surface measurements were found to be inconclusive with respect to downhole behavior. In some instances correlations could be drawn between surface accelerations and those downhole; in others surface vibrations were severe, while little was measured downhole; in still others downhole vibrations were dramatic, while nothing was indicated at the surface.

Operational recommendations are made based on experimental observations.
Application of High Sampling Rate Downhole Measurements for Analysis and Cure of Stick-Slip in Drilling
Authors: Pavone D. R. , Desplans J. P.
Published: December 2007

Optimal control of the drilling process requires that relevant physical models must be used while drilling. The reliability of these models must first be improved by comparing their results with actual downhole and surface data. Measurements of numerous drilling parameters and variables, sampled at high frequency, are then required.

Trafor is an MWD system designed and operated by the Institut Français du Pétrole for research on drill-string dynamics. It measures 15 downhole and 5 surface mechanical parameters. Because Trafor is fitted with an electric link adapted to rotary drilling, it transmits the downhole measurements to the surface in real time with a very high sampling rate of 1800 measurements per second. Furthermore, all the signals are fully synchronized. Hence, Trafor allows cross analysis between any signals, regardless of whether they are from downhole or from the surface.

New data recorded in a 1060 m deep well exhibit stick-slip behavior for various weights-ön-bit and rotary speeds.

Downhole data analysis coupled with numerical simulations shows that, in this field case, stick-slip occurred as an unstable drilling process. The origin of the instability lies in the relationship between the torque at the bit and the rotary speed. From this relationship, we can explain why stick-slip is known to disappear whenever the rotary speed (rpm) is increased or weight-on-bit is decreased. A stability analysis is used to derive operating conditions that prevent stick-slip.

Simulations of drilling with adjusted PID or with a downhole "anti stiçk-slip" tool are described. For both simulations, stick-slip can be cured.
Improved Log Quality with a Dual-Frequency Pulsed NMR Tool
Authors: Chandler R. N. , Drack E. O. , Miller M. N. , Prammer M. G.
Published: December 2007

A new pulsed NMR logging tool, the Series C Dual-Frequency Magnetic Resonance Imaging Log (MRIL®)*, has been in commercial service since January 1994. As a consequence of improved electronics design and the ability to "hop" between frequencies, the Series C tool provides high quality echo trains and MRIL® outputs at logging speeds up to 30 feet/minute, approximately 10 times faster than the Series B. Moreover, these design improvements allow for an extended operating environment, to temperatures as high as 155C and borehole conductivities as low as 0.02 Ohm-m. Laboratory-grade data obtained in situ allows for more complete relaxation analysis, leading to rock pore-size distributions and fluid identification.
NMR Pore Size Distributions and Permeability at the Well Site
Authors: Prammer M. G.
Published: December 2007

A fast and robust algorithm is presented for extracting T2 information from pulsed NMR logging data in real time. The degrees of freedom in the resultant T2 relaxation spectrum are adjusted to match the instantaneous signal-to-noise ratio of the data.

For single phase conditions and high bulk T2 relaxation values, the T2 spectrum is interpreted as a distribution of locally averaged pore sizes. A permeability estimate is computed by weighing and summing the spectral density components. The FFI/BVI permeability model, based on a T2 cutoff value of 25–30 msec, provides good immunity against partial hydrocarbon saturation and/or reduced bulk T2’s.
Subsurface Fracture Mapping Using Microearthquakes Detected During Primary Oil Production, Clinton County, Kentucky
Authors: Rutledge James T. , Phillips W. Scott , Roff Adam , Albright James N. , Hamilton-Smith Terence , Jones Steven K. , Kimmich Karl C.
Published: December 2007

Downhole microseismic monitoring tests were conducted in Clinton County, Kentucky to determine if microearthquakes associated with primary production could be detected on a scale of interwell distances (400 ft) and to determine if such microearthquakes could be used to map reservoir fractures. The oil reservoirs occur in shallow (750 to 2400 ft), low-porosity (< 2%), carbonate rocks of Ordovician age. The reservoir fracture system controlling the occurrence and flow of oil and its relationship to the local and regional geology is poorly understood. Discrete reservoir microearthquakes were detected at an average rate of 11 events per week and at distances up to 4000 ft in an initial monitoring test using a single, triaxial downhole geophone receiver. In a second monitoring test 2 downhole, triaxial geophone tools were placed in a monitor well 800 ft from a new, high-volume oil well. Over a 6-month period of continuous monitoring 165 discrete, high-quality, microearthquake waveforms were recorded. Approximately 11,000 barrels of fluid were extracted in the monitor area during the 6-month period. Presently, it is unknown whether or not the microseismicity is induced by production. Hypocenters computed for 121 events delineate 4 extensive (up to 0.15 square miles), low-angle, planar features striking approximately N65°E within the Ordovician reservoir depth interval. A composite fault-plane solution indicates a thrust focal mechanism. Such thrust structures are not observed in the surface-exposed Mississippian section, which lies above and is separated from the Ordovician section by a major unconformity of Devonian age. General relationships between the fractures revealed by the microseismicity and oil occurrence have yet to be demonstrated in the study area. The observed microseismicity occurs away from production wells, and to date, no new wells have been drilled into the mapped fractures along which shear displacement was detected.
First Monitoring Well in the Rabi Field: Design and Data Gathering
Authors: Alixant J-L. , Storey Martin
Published: December 2007

To optimise the Rabi Phase II field development plan, uncertainties on key petrophysical parameters had to be reduced below those normally achieved using conventional techniques. Core analysis results were not satisfactory because the reservoir sandstones are unconsolidated. It was decided to determine the petrophysical parameters in-situ, measuring certain reservoir properties using several independent techniques. A dedicated well was drilled specifically for this purpose.

This paper explains why it became necessary to drill the data gathering and monitoring well, and how the well was designed to ensure it would yield representative data. Important objectives were to improve the quality of base-logs, and to reduce environmental effects on time-lapse measurements. Key features of the well are described, including: A glass-reinforced Plexiglas (GRP) window, for time-lapse resistivity logging;Latch points over the reservoir section, for precise and repeatable depth-positioning of the Borehole Gravity Meter.

The comprehensive data acquisition programme is discussed, and open-hole logs are compared to initial cased-hole logs recorded in the GRP section.
A Transient Wellbore/Reservoir Model for Testing Gas Wells in High-Temperature Reservoirs, Part II. Field Application
Authors: Kabir C. S. , Hasan A. R. , Jordan D. L. , Wang X.
Published: December 2007

This paper describes the application of the transient wellbore/reservoir model developed in Part I of this work. The model allows forward simulation of wellhead pressure and temperature and bottomhole pressure as a function of time, given reservoir parameters and well completion details. Another simulator has been developed that directly translates measured wellhead pressure (WHP) and temperature (WHT) to bottomhole pressure (BHP) for subsequent analysis.

Forward simulation of wellbore pressure and temperature is a valuable tool for designing transient well tests. In particular, in a hostile downhole environment, the ability to estimate BHP accurately from wellhead measurements is an invaluable asset where downhole measurements may not be cost effective. Even in favorable situations, the simulator can aid both test design and interpretation.

Application of the simulator to field examples has helped us gain considerable insight into the mechanics of transient flow in the wellbore. For example, we observe a denser fluid towards the wellhead rather than at the bottom of the well because of the temperature effect. Consequently, decreasing storage behavior is observed at the bottom of the well.

Two field examples, obtained from a Gulf Coast gas field, are used to illustrate the capabilities of the simulators. Good agreement is noted between the computed and measured BHPs during both types of simulations.
New Cumulative Rate Convolution Analysis for Closed Chamber Test
Authors: Zhan Lang , Liu Weining , Chen Qinlei
Published: December 2007

Closed Chamber Test has aroused much interest recently for its short test time, simple operation and sound safety. However, variable wellbore conditions and rapidly changing sandface rate make interpretation difficult. In this work, the conception of effective wellbore storage coefficient proposed by Xiao and Reynolds1 is extended to obtain analytical functions of chamber gas pressure, effective wellbore storage and cumulative rate for a CCT. The influence of varying tool and reservoir parameters is discussed by using these functions. A simple numerical method is used to estimate cumulative rate by chamber gas pressure when friction and real gas behavior effects are important. As a principal contribution of this work, a Cumulative Rate Convolution technique is introduced for a CCT. It is shown that uncertainty coming from pressure differential to obtain sandface flow rate can be avoided by CRC technique. Skin factor S is directly determined in CRC plot, and initial reservoir pressure also can be estimated by extrapolating time function group to zero. It is shown that superposition model for shut-in data1 can be used in CRC technique, thus integrate interpretation including flow period and subsequent buildup transient data can be performed to enhance analysis confidence
Through Casing Formation Density Measurements
Authors: Wolcott D. S. , Vittachi Amal
Published: December 2007

Due to the high drilling costs associated with operating in a remote environment, there are strong incentives for reducing operating costs to maintain the economic viability of the field. One aspect of cost curtailment is reducing well evaluation costs. A solution is to utilize cased hole measurements which offer cost savings and reduced risk.

Using a specially modified wireline density tool, reliable measurements of formation bulk density can be obtained through casing. This measurement costs less than a measurement while drilling (MWD) density tool and reduces the chance of lost tool charges.

The cased hole density tool was constructed with source and receivers spaced further apart than on traditional open hole density tools allowing a deeper depth of investigation. A density correction algorithm has been developed to remove the effects of casing and cement to obtain a true formation density measurement. The tool has been run in over 15 wells, and comparisons with MWD and open hole wireline density data demonstrate the measurement is accurate and reliable.

The availability of a cased hole density tool has allowed greater flexibility in the design of logging programs. In horizontal and extended reach wells, the use of MWD density tools, which require full gauge stabilizers, can hinder steering. Also, MWD formation evaluation (FE) tools are limited to 8.5 in. or larger boreholes. By eliminating the MWD density-neutron tool in the open hole string, and making the measurement with the cased hole density, considerable operational and cost benefits can be realized. Because of lower cost and reduced risk the cased hole density tool offers a reliable and safe alternative to open hole density measurements.
Early Quantification of Hydrocarbon in Place Through Geostatistical Object Modelling and Connectivity Computations
Authors: Petit F. M. , Biver P. Y. , Calatayud P. M. , Lesueur J-L. , Alabert F. G.
Published: December 2007

A methodology of HIP quantification using geostatistical object simulations and connectivity calculations is proposed and tested on a gas field in appraisal phase.The object-modelling algorithm allows for a realistic representation of the shapes of sedimentary bodies and hence a fair modelling of reservoir heterogeneities and of their connections. As a classical volumetric computation is not appropriate due to a complex repartition of fluids and the presence of two types of gas, a static connectivity algorithm is used to quantify volumes which are connected to assumed gas-feeding sources; HIP values are deduced from this technique.

As major uncertainties exist on geological parameters, four scenarios are defined thanks to bootstrap calculations on well data; for each scenario, several geostatistical realizations are generated. Resulting figures provide the total uncertainty on GIP.

The sensitivity of results to the percolation cut-off is also estimated. The connectivity algorithm is questioned in terms of sensitivity to the grid block size.
Influence Functions for the Analysis of Well Test Data From Heterogeneous Permeability Distributions
Authors: Tauzin Eric , Horne R. N.
Published: December 2007

The simulated annealing solution technique has been a powerful reservoir characterization tool in geostatistics. This paper proposes an algorithm that uses this method to constrain the permeability distribution of a given reservoir model to the well test data collected at several wells. The technique can be used for single or multiple well tests.

In order to keep the execution time of this algorithm within an acceptable range, the perturbation on the pressure transient due to a local permeability heterogeneity is determined in the form of an analytic influence function. The results given by this approximation are compared to the results given by a simulator, and its use in the simulated annealing algorithm is defined according to its reliability. The algorithm is tested on an example, showing that the use of the analytic influence function allows considerable reduction in the computing time without decreasing the robustness of the method.
Porosity and Reservoir Thickness From Core, Log, and Seismic Measurements
Authors: Marion D. P. , Jizba D. L. , Vernassa Sylviane
Published: December 2007

We present a method that uses combined information acquired at core, log and seismic scale for improved reservoir delineation and characterisation. In the paper, we illustrate how the method is applied to estimate porosity and reservoir thickness on a carbonate oil field. This work shows that once proper calibration is performed using core and log measurements, seismic measurements can be used to quantify lateral variations of rock properties and hence constrain reservoir simulation models.
Integrating Well Log Data, Drilling Data, and Laboratory Data for the Determination of Maximum Drawdown Limits in the Presence of Weak Sands
Authors: Pennington W. D. , Edwards D. P.
Published: December 2007

The ability to predict sand failure in producing wells is important for the economic planning of the development and management of oil and gas reservoirs. Anticipated failure of weak sands often limits the production rates from wells, perhaps unnecessarily in many cases. Sand failure can occur either as a transient phenomenon, as perforation tunnels enlarge in response to shear failure in the vicinity of the borehole, or it can occur continuously, as intact rock crumbles and is produced into the wellbore. These failure conditions can be predicted from wireline logs, estimates of in-situ stress, and laboratory tests of strength on core plugs. The strength tests on core plugs can often be divided into two classes: those that indicate that the rock contained a plane of weakness, on which failure occurred easily; and those that indicate the rock was essentially intact. The strength of the weaker class of rocks is indicative of the "rock mass strength," including flaws and planes of weakness; residual strength tests conducted on these samples can be used to predict a reduced state of stress after initial failure. The strength of the stronger class of rocks is indicative of the "intact rock strength" and is used to predict the potentially catastrophic conditions of continuous sand production, when compared with the reduced state of stress after initial failure. The recognition of the two classes of core plugs together with the assumption of a predictable reduced state of stress leads to more optimistic drawdown scenarios than would otherwise be determined.

This model has been applied to a number of fields, including one from the Gulf of Mexico which was discovered very near an older field known to contain extremely weak and unconsolidated sands. After a thorough analysis, it was concluded that the newer field was in fact quite strong, and production rates were increased considerably beyond those that had been considered to be safe prior to the study.
Gas-Lift Optimization in a Large, Mature GOM Field
Authors: Everitt T. A.
Published: December 2007

This paper describes the processes and results of an extensive gas-lift optimization effort executed at the field level in South Pass Block 24 (SP24) of the Gulf of Mexico. The processes described herein include data gathering, problem identification, and problem resolutions which resulted in a 50% reduction in lift gas requirements.
An Updated Data Gathering System To Optimize Production Operations
Authors: Patterson J. C. , Curfew J. V. , Bucaram S. M.
Published: December 2007

Failure control is a critical path to optimizing operations in today’s petroleum industry. Failure control in its simplest form is failure analysis with the goal of achieving corrective action. Accurate records and meaningful reports are a key part of any failure control program. This paper is the third in a series involving the data gathering and processing system used by Atlantic Richfield to optimize production operations and discusses the new PC system version. Application is demonstrated by identifying some rod pumping problems, suggested solutions, and results.
An Innovative Cell To Control the Gas-Tightness of Cement Slurries
Authors: Degouy D. G. , Large P. R.
Published: December 2007

This paper presents an innovative gas migration test cell, fully automated, developed to evaluate cement slurries for gas well cementing. A low pressure regime, consistent with the actual hydrostatic pressure exerted by the cement column, is applied in the cell. The gas migration process is therefore only governed by the evolution of the intrinsic characteristics of the slurry. A comparative study on several commercially available additives and a parametric study on one of these additives have been undertaken. Results obtained are presented and discussed.
Downhole Performance Evaluation of Blast Furnace Slag-Based Cements: Onshore and Offshore Field Applications
Authors: Leimkuhler J. M. , Rambow F. H. K. , Warren P. B. , Javanmardi K. , Ladner B. S. , Smith T. R.
Published: December 2007

Shell has used BFS cements on over 160 oil well cementing operations as part of an effort to develop and expand the understanding of blast furnace slag (BFS)-based cements. Well types include major deepwater development wells to sidetracks drilled with a workover rig. Downhole conditions range from cold deepwater applications to shallow thermal wells subjected to cyclic steam injection.

To date, the field performance of slag-based cement has met or exceeded expectations. Formation integrity tests, bond logs, and production data indicate good annular isolation. Casing shoe integrity test datafrom exploratory and development wells show a lower incidence of remedial squeezing prior to drilling ahead as compared to Portland cements. Contrary to previously reported bond-log evaluations, conducted under laboratory conditions, downhole bond logs under saturated conditions indicate an improved casing/cement bond with time. Production data from wells with dual completions indicate good zonal isolation between perforated intervals. Leak-off test data for slag-based cement jobs conducted in the Gulf of Mexico are reported for each casing size. Field data for squeeze cementing casing shoes, liner tops, and casing annuli are also presented.
Hydrate Formation/Inhibition During Deepwater Subsea Completion Operations
Authors: Peavy M. A. , Cayias J. L.
Published: December 2007

This paper describes hydrate issues related to the design and success of a fast track development project for three Gulf of Mexico deep water subsea gas well completions. The project challenge required development of specific hydrate inhibition steps in order to minimize the occurrence of hydrates during well completion and flow testing due to cold mud line temperatures (45-55°F, 7-13°C), low reservoir temperatures (100-115°F, 38-46°C), and high bottom hole pressures (3,000-4,000 psi., 21-28 MPa.).

Basic hydrate formation theory and prediction were reviewed and integrated into a hydrate prevention program for the completion and testing program for this project. Hydrate prediction utilized temperature and pressure prediction modeling, overlay of potential events on hydrate equilibrium dissociation curves, and subsequent correlation to mud line temperature and pressure gauge measurements. Three areas of major concern for hydrate formation were during well flowback, shut-ins, and well kill. Hydrate inhibition included the use of inhibitors, and both surface and downhole injection systems involving various mixtures of glycol, methanol and IPA dependent upon the sequence of well events.
Blistering of Thermoplastic Materials Used in the Petroleum Industry
Authors: Jarrin Jacques , Dewimille Bernard , Devaux Elizabeth , Martin Joseph , Piques Roland
Published: December 2007

Experimental and theoretical results concerning the blistering of thermoplastic polymers used in the petroleum industry are described. Cells working with methane up to a pressure of 100 MPa have been equipped with an LVDT and temperature sensors to record the thickness variation, pressure and temperature of the samples during the tests. The results from the LVDT sensor have been used to model the different phases of the tests. The model described is based on the volumetric variations of the samples under gas pressure. This model estimates the Von Mises stresses in the materials during the tests. A comparison with the mechanical strength of the samples shows that the orders of magnitude are enough to predict the blistering of the materials tested.
A Review of Many Improved Recovery Methods
Authors: Crawford Paul B.
Published: December 2007

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

During the past 20 years members of the petroleum industry have proposed more than petroleum industry have proposed more than fifteen new or novel recovery methods for increasing the ultimate oil or gas recovery. This paper is a general review of these new methods. A simple description of the new and improved recovery processes and their range of application is presented.

The methods discussed include wet combustion, forward combustion, reverse combustion and combustion with fuel injection. The miscible process of high pressure gas, enriched gas and LPG slugs, are covered. Use of micellar solutions, alcohol and foam flooding is covered.

The application of atomic bombs for well completions is discussed.

Introduction

A new oil recovery method was field tested near Throcknmorton, Texas approximately 35 years ago. The new method of steam flooding was to launch thermal oil recovery methods on their way. It seems that very little work in new oil recovery methods was underway until following World War II. At that time oil recovery by insitu combustion, steam drives and miscible high pressure gas recovery programs occupied considerable interest in some of the research laboratories.

At the present time thermal oil recovery takes on many different forms of operation, steam drives, hot water floods, forward combustion, forward wet combustion reverse combustion, combustion with fuel injection, combustion followed by waterflooding are all different aspects of the thermal recovery portfolio. Steam soaking should be included portfolio. Steam soaking should be included since it has been demonstrated to be a process which will increase the ultimate oil recovery method in economic times. In a similar manner miscible displacement now includes five different processes.

The purpose of this paper is to review a large number of these new recovery methods and provide an indication of their likely range of application.
A Novel Process for Profile Control in Thermal Recovery Projects
Authors: Morgenthaler L. N. , Schultz H. A.
Published: December 2007

Gels formed by crosslinking block copolymers have been developed for control of steam injection profiles in Shell’s thermal recovery projects in California. The combination of temperature dependent crosslinking and excellent thermal stability exhibited by these gels has been exploited to improve steam injection profiles with greater success and at lower cost than achieved with conventional profile control methods. Laboratory studies of gelation rate and gel strength to evaluate formulations for field application will be reviewed. More than forty successful treatments have been performed to date and validated using injection profile surveys. In every well, steam injection into the treated interval has been eliminated. Payout time, based on steam cost savings alone, has averaged less than two months.
Super Thick Fluids Provide New Answers To Old Fracturing Problems
Authors: Alderman E.N.
Published: December 2007

Extremely viscous fracture fluids have provided a new tool for stimulation of wells provided a new tool for stimulation of wells which previously have not been considered good candidates for conventional fracturing techniques. Soft sands and more permeable formations are the primary targets for the super thick fluids, but they have also performed well in retreatments and other performed well in retreatments and other applications.

Super thick fluids function by creating wider fractures and providing better prop penetration of the reservoir. The extremely penetration of the reservoir. The extremely high injection rates and large volumes of present treatments are not required. present treatments are not required. This paper will discuss the various oil-base and water-base fluids currently available. A theoretical comparison of fracture area, conductivity increase, and productivity increase obtained by conventional and super thick fluids under similar conditions is presented. Comparative field results of conventional and super thick fluids are also shown.

Introduction

A brief history of hydraulic fracturing fluids since the inception of fracturing in the early 1950's might be summarized as follows:

High-viscosity gelled oils and emulsions Refined oils Lease ails, water and low-viscosity, gelled oils Gelled water

In the early days of fracturing, viscosity was required to achieve fracturing efficiency. Pump rates were low and friction pressures were high. pressures were high. With the introduction of early day fluid loss additives, less viscous refined oils were successfully used. Pump rates were still limited by high friction pressures and pumping equipment. pumping equipment. Improved fluid-loss additives and pumping equipment led to an era of fracturing pumping equipment led to an era of fracturing with even lower viscosity fluids, such as lease oils, water and low-viscosity gelled oils. Pump rates increased because of the lower friction pressures.

The introduction of gelled water systems, with the natural properties for friction reduction and fluid-loss control started another era continuing even to date. The gelling materials, guar gum, cellulose derivatives or snythetic polymers have almost completely replaced treatments with oil-base fluids.
A New Method for Communicating Downhole Sensor Data Within the Annulus of a Production Well
Authors: Leggett III J. V. , Green B. R.
Published: December 2007

A high data rate (10–40 Baud) wireless communication method for transferring data and controlling downhole mechanisms has many applications in well production technology. This paper describes the development, design of a prototype, and the method where tests were performed to confirm the acoustic communication behavior in the annulus of a production well, in viscous fluids as a function of depth to 7500’. The tests were performed to determine acoustic attenuation, effect of fluid viscosity, effect of head pressure, acoustic noise levels, and their effect upon baud rate. Both time and frequency domain signals were evaluated to determine the effect on up-link and down-link transmissions. Echoes and other types of interference were also measured at different depths to further investigate the signal path. A key goal was to define attenuation in dB/1,000’ (of depth) for several fluid viscosities at various frequencies.

This method can monitor multiple downhole sensors of pressure, temperature, viscosity, flow, etc., providing stored information from memory or real-time downhole conditions. Additionally, this method can provide "real-time while tripping" communication for gamma ray depth correlation during perforating and other depth control applications. Other potential applications include safety valve, "frac" monitoring, and field production zone control. "Distributed processing", "multitasking", and "self-adaptive to changing well conditions" are key features which make this method ideal for a broad range of applications.
Drop-Drop Coalescence in Oil/Water Separation
Authors: Hafskjold Bjøin , Morrow Thomas B. , Celius Harald K. B. , Johnson David R.
Published: December 2007

This paper gives an analysis of the performances of two oil/water separators. One is a laboratory model using a clean oil/water system, and the other is a test separator from an offshore Middle East field. In both cases, we considered the separator's ability to produce clean oil, i.e., the concentration of water in the effluent oil. The analysis of the two separators was based on measurements of the effluent oil quality, inlet water cut, flow rates of water and oil, the overflow rate, and the retention time. For the model separator, we performed detailed batch tests in order to relate the performance of the separator to convenient laboratory measurements. The relationship was made with a mathematical model and a corresponding computer code that was used to predict the separator performance on the basis of the batch test data, and to parameterize the performance data for the two separators. We found that the droplet coalescence rate and the oil/water separation rate were highly nonlinear functions of time, which means that coalescence was an important separation mechanism in both separators. This makes the separator sensitive to changes in the flow rates and the oil pad thickness. The residence time was the critical design parameter for both separators, whereas the overflow rate was found to be of little importance. Due to the importance of coalescence, an increase in the inlet water cut would improve the separator efficiency and actually produce oil with less water.
Block Tests Model the Near-Wellbore in a Perforated Sandstone
Authors: Mason J. N. , Behrmann L. A. , Dees J. M. , Kessler Nicolas
Published: December 2007

Most oil and gas wells are cased and perforated. Perforating is usually the most important part of completing a well because it has a major impact on well productivity. However, conventional perforating studies use single-shot perforations into cylindrical core targets, which do not provide information on the interaction between phased multiple perforations.

Four laboratory ‘Block Tests’ were performed during 1991 and 1992, in a joint venture between BP Exploration, Schlumberger, Elf Aquitaine and Oryx Energy. A 4 3/4" (121mm) wellbore was drilled through each of the 25 ft3 (0.7m3) blocks of Berea sandstone. Each block was loaded into a large ‘stress frame’ and placed under confining stress before a 3 1/2" (89mm) diameter casing was cemented in place. The four tests included underbalance and overbalance perforating, well killing, clean-up and acid stimulation. A pack-off tool was used to measure the flowrate from individual perforations.

The differences between perforations and the interactions between them dominated the behaviour of the large sandstone blocks. Variability in the apparently homogeneous Berea sandstone, over just a few inches, meant that no two perforations behaved in exactly the same way. The work showed how the most productive perforation can become the least productive after killing a well, and how a poorly designed kill pill can give clean-up from very few perforations. Underbalance and overbalanced perforating did not give the expected results.

By simulating the downhole situation with real phased perforations, the Block Tests improve the understanding of what happens downhole, allowing better design of well operations.
The Potential for Sand Production: Assessment by Finite Element Modelling
Authors: Somerville J. M. , Smart B. G. D. , Zoller S. L. , Farquhar R. A.
Published: December 2007

This paper presents the results of a study into the potential for sand production from a Rotliegendes reservoir rock. The approach is purely mechanical in that debris will be produced from the rock when the principal stresses applied are greater than the yield strength. An analytical solution to the stress concentration around a hole in an hydrostatically loaded rock has been developed by Wilson and modified by Smart et al. This approach predicts the extent of a zone of yielded material around the hole. For application in non-hydrostatic stress conditions and to accommodate the geometry of a perforation adjacent to a borehole, finite element analysis is used to determine the extent of the yield zone as no analytical solution is possible. Correlations developed from laboratory mechanical testing of Rotliegendes samples are used to predict the area of the yield surface produced in yielded rock and the mass of debris generated from that surface. The debris created may act as a source of solids which may be produced with the reservoir fluids. The study reported here was limited to debris creation only.
Experimental and Numerical Modeling of Convective Proppant Transport
Authors: Barree R. D. , Conway M. W.
Published: December 2007

Slurry transport and settling experiments were conducted to improve current descriptions of proppant transport. Results of these experiments were used to formulate a new slurry transport model which was incorporated in a fully three-dimensional fracture simulator. The model was tested and verified against experimental observations of slurry transport in a 4 foot by 16 foot slot model. Results of the study indicate that proppant slurry transport can be accurately modeled when the effects of single particle settling, density driven flow, particle velocity profiles, and slurry rheology are accounted for.
Incorporating Shallow Marine 3-D Seismic and High-Angle Slant Drilling To Develop Reserves Under Lake Newell
Authors: Slade J. M. , Syhlonyk G. E. , Krishnan Chris , Rojek Otto , Borchert Guenter , Baxter W. C.
Published: December 2007

The Glauconitic channel fairway in the Countess/ Johnson Fields of Southern Alberta has been postulated for many years to extend underneath the man made reservoir, Lake Newell. The use of 3-D seismic and construction of an extended reach slant drilling rig provided the means with which to exploit these hydrocarbon accumulations with an acceptable risk.

The program consisted of 22 wells drilled from four different pads surrounding Lake Newell. All wells were drilled slant with inclinations of up to 72 degrees and total measured depths of more than 2900 meters. MWD data was incorporated with seismic structure data to constantly monitor depths. Exploration wells were strategically placed to provide maximum reservoir information without compromising reservoir development strategies. Contingency planning was used to allow for drilling program modifications without loss of drilling time.

To expedite the project, facilities design and exploration drilling commenced at the same time. Environmental considerations and the increasing recreational use of Lake Newell required special facility considerations. The use of concurrent drilling and completion activities on the pads provided significant time savings and allowed production during drilling operations.