bluuebunny/crossref_metadata_2025 huggingface dataset:
Return Fluid Analysis From the Sadlerochit Formation, Prudhoe Bay, Alaska: A Laboratory Study—Part II
Authors: Fambrough J. D. , Brady J. L. , Almond S. W.
Published: December 2007

Part I1-the field study, was presented as SPE 18223 at the national SPE meeting in Houston in 1988. It reported the results of a series of ionic analyses on returned fluids collected after a variety of acid treatments and the results of laboratory solubility tests on disaggregated core material. The field study had raised some key issues concerning the stimulation of the Sadlerochit formation. When and where was the precipitation of silica occurring downhole? Did this precipitation of silica result in significant formation damage? What was the relationship between the Si:AI ratios seen in the return samples analysis and those seen in standard acid solubility tests and acid core flow tests? Would an increase in the ratio of HCI:HF increase the Si:AI ratio and thus provide a more effective treatment? Was the Sadlerochit formation a source for the high ferric iron seen in the returned fluids?

To answer these questions an extensive laboratory study using Sadlerochit core plugs was initiated. SEM, thin sections, porosity, and permeability tests were done before and after acidizing a series of core plugs. The use of a high temperature, high pressure, ported flow cell provided the capability to monitor the acid treatment as it moved through each section of core material. Different HF acid systems (12% HCI:3% HF, 6% HCI:1.5% HF, 13.5% HCI:1.5% HF) were pumped through a set of core plugs and the effluents monitored under both continuous flow and flow after a shut-in time.

The results indicate that the Si:AI ratio decreases as the acid moves through the core. Lowering the HF concentration decreases the Si:AI ratio and the rate of change of this ratio as the acid reacts with the formation. Increasing the HCI:HF ratio had little effect on the Si:AI ratio of the spent acid. Si:AI ratios similar to those seen in the field study were seen only after a 14 hour shut-in at temperature with the Sadlerochit core material. No significant change in permeability was obtained after the silica was precipitated during the shut-in test. This suggests that although a large quantity of precipitated silica is left downhole, no significant loss in permeability occurs. This agrees with the overall production improvement seen in the HF acid treatments of the Sadlerochit formation.
Hydraulic Mining of Permafrost Placers by Boreholes
Authors: Khrulev A. S.
Published: December 2007

The results of investigations and commercial tests of borehole hydraulic technology and equipment for gold and tin production from frozen placers through boreholes are given in this article. The variants of mining of small and thick placers through boreholes and the description of borehole equipment depending on conditions of use. The positive sides of borehole mining's application, problems appeared in the course of test and ways of their solution are shown.
Open-Cast Underground Technology of Permafrost Placer Mining in the Arctic
Authors: Lavrov N. P. , Lukjanov D. N.
Published: December 2007

Perennialy frozen placers at depth of 10 to 30 m may be profitably mined by combining the opencast and underground mining procedures. According to this method, the placer is at first partially mined in opencasts, and then the underground mining is used to recover the rest of it.

The underground mining is carried out by means of systems of chambers with gravel rib pillars left or artificial backfills produced. The technique involving freezing of water is applied to construct artificial pillars. Overburden rocks are used as the stowing material. Underground gravels are recovered and transported to the washing site.

The opencast-underground technique is the most expedient for mining deep placers considering the problems of recultivation under the Arctic conditions.
Comparison Between Measured Global Ice Loads and Geotechnical Response of Arctic Offshore Structures
Authors: Blanchet D. , Hewitt K. J , Sladen J.
Published: December 2007

Global ice load criteria govern the stability of an Arctic offshore structure and its foundation. This paper reviews six case histories in which ice pressures have been measured, and the foundation response has been predicted and monitored. The global loads inferred from the two methods are compared and discussed.
Development of an Alaskan North Slope Soils Database for Drill Cuttings Reclamation
Authors: Schumacher J. P. , Gillespie J. D. , Malachosky E. , Hampton P. D.
Published: December 2007

Reclamation of processed drill cuttings provides environmentally acceptable construction material for roads and pads thus minimizing the need to excavate materials from surface gravel pits. Regulatory agency policy goals of reduction in surface disturbance of Arctic environments, reduction of waste, and recycling of a natural resource can be achieved.

In order to adequately assess the compatibility of drill cuttings with the North Slope environment, information regarding the chemical composition of background soils is required. This paper reports on the work done by ARCO Alaska, Inc. to establish a primary database on the chemical composition of uncontaminated soils and gravels from various North Slope sites. Background samples have been analyzed by EPA Method 3050 techniques, and ranges for metals and salts have been accepted by the Alaska regulatory agencies.

Additionally, development of a secondary elutriate test method based on EPA Method SW924 is described as it was applied to analysis of background materials and drill cuttings. The technique evaluates the leachability of chemical constituents from various types of monofill materials.

Data are presented for materials excavated from several wells in the vicinity of the Prudhoe Bay Field. Processed and unprocessed drill cuttings are compared through analysis of the chemical constituents. Results indicate that the removal of clays and other fine particles through the water-based processing technique produces high grade construction material.

The techniques described in this paper are broadly applicable throughout the Arctic. Establishment of a chemical background database for the North Slope of Alaska will assist in minimizing environmental effects of placement of excavated material. In addition, techniques for processing and analyzing materials recovered from drilling operations in Alaska may be applicable to other Arctic areas where exploratory or development drilling is occurring.
Drilling Wastes Management for Alaska's North Slope
Authors: Fristoe B. R.
Published: December 2007

In the early 1980s the State of Alaska's Department of Environmental Conservation determined that drilling waste disposal practices at the oil fields on the North Slope were not adequately protecting the environment. New regulations were promulgated in October, 1987 that required improved containment of wastes and better monitoring of waste disposal sites. Industry and the state have been working together to develop methods that will meet the requirements of the new regulations and a number of these methods have been tried in the field over the past few years. The methods, including waste reduction, injection of drilling wastes, deep hole burial using permafrost for containment, shallow hole burial using permafrost for containment, and treatment of waste for use as construction material, are discussed in context with the status in the development of each technology, concerns for each technology that the state has, and regulatory schemes that have been developed for each technology. Great strides in a number of these options have occurred over the past five years; however, extensive data on the new technologies have not been gathered and it is anticipated that refinement of them will continue for the foreseeable future.
The Relationship of Telluric Currents to the Corrosion of Warm Arctic Pipelines
Authors: Sackinger W. M.
Published: December 2007

Warm pipelines may be elevated above ice-rich permafrost, but buried in unfrozen ground or in ice-containing permafrost which is regarded as mechanically thaw-stable. In northern regions, the concentration of ionospheric electrical currents causes not only aurora borealis but also a time-variable magnetic field at the earth's surface, and the induction of electrical currents in the soil and in pipelines. A model is presented for electrical current flow in a typical warm pipeline segment, including both buried and elevated sections, soil resistances, corrosion protection sacrificial anodes, and regions of damaged pipeline coatings. The circuit is analyzed, and specific conditions under which corrosion currents may leave the pipeline at locations of coating damage, thus causing corrosion, are identified. The flow of telluric currents both into and out of the sacrificial anodes which may be connected to the pipeline is described, and the conditions for this are discussed. Certain conditions are described under which sacrificial anodes may become disconnected from the pipeline. Possible methods for alleviating corrosion related to telluric currents are presented, including the choice of grounding locations, insulating flanges, and adaptive impressed-current sources.
Offshore Development in Iceberg-Infested Waters With the Use of a Concrete Protective Barrier
Authors: Broughton P. , Davies R. L. , Berthin J. C. , Martin J.
Published: December 2007

This paper describes novel methods for the development of offshore oil fields within iceberg infested waters, at locations with water depths of up to 200 metres. The scheme involves the construction of a Protective Barrier which completely surrounds and protects the oil production platform. The production platform facilities, which are located inside the Protective Barrier, may either be supported off a fixed steel structure, or alternatively off a jack-up platform, or alternatively off a specially developed floating production unit. The quite separate Protective Barrier is constructed in a cellular arrangement from reinforced or pre-stressed concrete, and has sufficient mass through its own weight, together with the weight of solid ballast, placed within the cells, to resist external forces due to either icebergs or wave action. The feasibility of the scheme is demonstrated for a typical oil field development in 80 metres of water. The paper provides the overall sizes and quantities of materials used in the construction of the Protective Barrier and of the structure required to support the production facilities, together with a description of the methods of installation of the production platform within the Protective Barrier.

In this development scheme, a major point has been to reduce the overall quantities during construction and hence the anticipated overall development costs, together with a reduction in the overall schedule, as against more conventional methods of offshore field development in these areas. It is considered that the development scheme, as described in the paper, will allow the economic development of offshore oil and gas fields in iceberg infested waters, which hitherto have remained undeveloped for economic reasons.
Thermosiphon-Based Designs and Applications for Foundations Built on Permafrost
Authors: Zarling J. P. , Haynes F. D.
Published: December 2007

Thermosyphons have been used across Alaska and northern Canada as a means of stabilizing foundations built on permafrost. This paper describes a number of different applications including details of the installations. A brief discussion of the design methodology is also presented.
Optimizing Fracture Stimulations in the McArthur River Field, Hemlock Reservoir, Utilizing Historical Results and Improved Technology
Authors: Schoffmann A. B.
Published: December 2007

This paper describes a study undertaken to determine the feasibility of hydraulic fracture stimulations in the McArthur River Field, Hemlock formation, Cook Inlet, Alaska. The study reviews the results of Hemlock treatments pumped prior to 1989, the factors influencing the success or failure of the treatments, and steps that could be taken to optimize future treatments. Through 1988, 18 fracture treatments had been attempted to improve productivity from the Hemlock reservoir, a sequence of unconsolidated to poorly consolidated sandstones and conglomerates up to 500 feet thick. The study considered the sensitivity of job success to reservoir properties, the mechanical condition of the well, and fracture stimulation design. To aid in this evaluation, a three-dimensional1 hydraulic fracture simulator (GOHFER) was utilized to match selected previous treatments. In addition, a lab testing program to investigate fracture conductivity under reservoir conditions was undertaken.

The study demonstrated that the majority of previous Hemlock fracture stimulation treatments have been successful when judged by generic economic criteria. A number of critical job design and candidate selection criteria appear to significantly enhance the prospects for a successful hydraulic fracture stimulation. These criteria are discussed in the following. Finally, the results of a successful producing well treatment using information gained from this work are presented.
Environmental Activity Management and Control Exercised by Pipelaying Association
Authors: Shishov V. N.
Published: December 2007

This report deals with the problems covering the environmental control under conditions of broad-scale and intensive laying of various pipelines (including high-capacity ones, dia. 1420 mm, P = 5 MPa) in various natural and climatic conditions ranging from Far North to the southern regions (the Caspian Sea).

The laying of high-capacity and extended pipelines entails sizable ecological damage to lithosphere and surface waters.

The environmental management includes elimination of constructional damage caused to the route of pipelines, perfection of equipment and techniques of construction with regard to ecological criteria, reduction of environmental impact in the areas of own facilities (motor depots, industrial bases, etc.), environmental control, monitoring and training of the personnel.
Environmental Safety of Construction of Gas and Oil Facilities in Arctic Regions
Authors: Mazur I. I. , Mazur E. V.
Published: December 2007

This report deals with the estimate and provision of environmental safety in the course of construction of oil and gas facilities: ground facilities (compressor and pump stations and the like) and extended underground pipelines. The analysis of accumulation of constructional technogenesis accompanying these two major types of construction of oil and gas facilities made it possible to elaborate the analytical models of accumulation of constructional technogenesis - ecological damage and mechanism of occurrence of ecological failure of the formed natural and technical (oil and gas) geosystem. The concept of the complex engineer-and-ecological support of construction of oil and gas facilities is based on the theory of environmental safety. The report presents its components, major objectives and the results obtained.
Programming Considerations of a Production Data-Acquisition System
Authors: Greenhill K. L. , Dennison J. A.
Published: December 2007

A PC based computer system has been designed and implemented in which field personnel acquire oil and gas production data using handheld terminals. This data is uploaded to PC's for field management; it is then transferred to PC's at the area office for production reporting. From the area office data is uploaded to a mainframe computer for accounting purposes. The flexibility of this comprehensive data collection system put a large burden on the programming staff to implement both the handheld software and the PC database system. Memory constraints on both platforms were partly met through the sophisticated implementation of program overlays. The configurational nature of the software posed a challenge in testing the myriad of data flow paths. Although much time and effort was spent testing the software during development, many errors were only found when it was installed in the field. Aside from the size of the programs, a major difference between this field data collection application and other similar applications is that the same PC database system runs both at the field and the area level. Daily changes to the field databases are uploaded via modem to the area database. If changes are made to the area databases, these are downloaded to the appropriate field during the daily call. Verifying that all changes are passed up and down without destroying the integrity of the databases has been a significant task. With the challenges of these design considerations resolved, the system as implemented reduces multiple data entries and the time required to generate reports for the eight fields and four area offices where it is currently implemented.
Scooter a Real Time Expert System for Process Control: Application to Gas Dehydration on Offshore Platforms
Authors: Cordier B. , Gokana D. , Huynh C. T.
Published: December 2007

This paper presents research conducted by Elf Aquitaine within the framework of the PLATINE project (ref. 1) into the development of an advanced remote control system.

PLATINE (an acronym derived from the French PLATeforme INhabitéE or unmanned platform) is a full size unmanned offshore hydrocarbon production platform, designed to operate with yearly maintenance and planned inspection visits (along with a number of random one-day visits).

SCOOTER is an advanced remote control system developed for the project

This paper describes the main functions the system is expected to fulfil, the technical choices made, the methodology used and the results obtained for the control and supervision of a gas dehydration unit to be installed on the unmanned platform.
Reevaluation of Hydrocarbon Reserves in Old Fields Through Cased-Hole Interpretation: A New Approach
Authors: Cosentino L. , Spotti G.
Published: December 2007

The widely recognized importance of the re-evaluation of existing hydrocarbon fields has focused the attention of oil companies on the problem of cased hole logging interpretation.

Cased hole logs actually provide a lot of information. However, their response, particularly for the Density log, is heavily affected by the presence of casing and cement. For this reason, cased hole recordings are mainly utilized from a qualitative or semi-quantitative point of view by applying empirical corrections to the measured values.

A new algorithm for the automatic correction of all the environmental effects has been developed for the Density log. It is based on the evaluation of the relative contribution of casing and cement to the bulk density measurement. Thence, also corrosion can be taken into account. Casing collars and other disturbances are corrected through a multiple linear regression technique. Neutron, Sonic and Gamma Ray logs undergo a calibration procedure and their reliability is accurately verified.

A case study relevant to an old Italian gas field is presented.
A Geostatistical Interpolation Method From Only Two or Three Wells
Authors: Yang An-Ping
Published: December 2007

It is generally thought that data from at least 20 or 30 wells are needed to generate the statistics for inter-well interpolation. We show in this paper that it is possible to use as few as two wells to generate a cross-section, and to use as few as three wells to generate a three-dimensional reservoir description. Geostatistics describes a reservoir with two models: a distribution model that deals with data values, and a spatial correlation model (the variogram) that deals with variation from location to location. Examples are considered for the Kern River Field in California to show how the method can be applied. Three major areas of application for geostatistical interpolation include computer visualization of the reservoir, Monte Carlo simulation for sensitivity study, and reservoir heterogeneity characterization for other reservoir models.
High Recovery in a Volatile Oil Reservoir: Case History
Authors: Siti B. , Vignati L. , Usikalu A.
Published: December 2007

A recent study carried out on sane levels of Mbede Field in Nigeria, containing volatile oil and in the presence of primary gas caps, showed quite satisfactory recovery factors. More than 50% of the O.O.I.P has already been recovered from two out of the four hydrocarton bearing levels, while in the remaining two the present recovery factor ranges between 35 and 45%.

These excellent values must be ascribed to the good characteristics of the rock and the oil and to the remarkable "gravity segregation" that is one of the primary drainage mechanisms.

Some forecast cases have been analyzed. They show that the final recovery factor ranges between 52 and 71%. The lowest recovery factors are encountered in the levels where the aquifer is present as a further drainage mechanism.
Analysis of Hangingstone Multiwell Cyclic Steam Pilot: Three Years’ Performance History
Authors: Sarioglu G. , Khallad A. I. , Brown M. W.
Published: December 2007

The purpose of this paper is to review the status of a 13 well pilot program to utilize cyclic steam stimulation as a commercially applicable process for the Athabasca Oil Sands deposits in Alberta, Canada.

In the Athabasca deposit, bitumen bearing sands are contained in the lower Cretaceous McMurray formation, which is a clastic sequence deposited in a predominantly fluvial environment. The reservoir consists of a series of stacked channel sands. These sand bodies can be divided into distinct units based on stratigraphy and ichnology. These channel sands vary both laterally and vertically and correlation of individual sands is quite difficult. The bitumen is very viscous 1,000,000 cp (1000 Pa.s) at original reservoir temperature with an API gravity of 8. The effective permeability of the reservoir at original conditions is very low because of high bitumen viscosity and low connate water mobility. Therefore, to inject steam at commercial rates, artificial fractures are induced.

Prior to the 13 well Pilot, Three Single Well Tests (SWT) were conducted in the nearby area, between 1985 and 1990. During this period operating problems related to completion, sand handling, fluid production have been overcome and considerable progress was made towards optimizing operating strategies such as fracture configuration and cycle steam slug sizes using the field data and a thermal simulator.

In view of the encouraging performance of the single well tests and simulation results construction of a thirteen well pilot started in 1989.

To date, 9 wells have completed 2 cycles and one well in the center of the pilot 3 cycles of cyclic steam operation.

The results of these ten injector/producer wells will be summarized together with five observation wells and alternate strategies to improve the performance will be discussed.
Seismic Monitoring of a Steamflood at South Casper Creek Oil Field, Wyoming
Authors: Johnston P. F. , Wachi N.
Published: December 2007

Repeat 3-D and cross-well seismic surveys are used to monitor a steamflood thermal EOR pilot project at South Casper Creek Oil Field, Wyoming, USA. Seismic travel-time changes are observed after 7 and 12 months of steam injection, and can be used to infer intra-well details of the steamflood process.
Numerical Modelling of Cyclically Steamed and Fractured Oil-Sand Reservoirs
Authors: Chan M. Y. S. , Sarioglu G.
Published: December 2007

Current conventional thermal reservoir simulators are poorly equipped to account for fracturing phenomena such as those encountered in cyclically steamed oilsand reservoirs in Alberta, Canada. This paper describes a procedure by which the fracture characteristics can be, at least partially, incorporated into such simulation studies. By using a fracture model, the fracture characteristics are "translated" into pressure, temperature and saturation distributions which the thermal reservoir simulator can utilize in subsequent studies. The logic and procedure described is easily extendable to include other unconventional information which are otherwise often ignored in numerical modelling studies. The procedure was successfully tested on a number of cyclic steam simulated wells in the McMurray formation of the Athabasca oilsand deposit in Alberta, Canada. The results from four such applications are given as examples in this paper.
Use of External Geological and Engineering Information for Well Test Design and Interpretation
Authors: Du Kui-Fu , Stewart G.
Published: December 2007

In interpretation of well tests especially model selection and verification, two parallel and equally important sources of diagnosis are widely used by reservoir engineers. They are pressure transient testing itself and the knowledge of the relevant geological and other engineering information on the well/reservoir being tested. The former is based on significant shapes displayed on the test signal, which may correspond to features (behaviour, structures etc) of the tested reservoir. The latter is to predict the reservoir dynamic behaviour on the basis of all the available external geological and engineering data. They are complementary to each other. The interpretation cannot be done correctly using only one of them.

Previous work on the application of artificial intelligence (AI) techniques to this domain only attempted to automate the former diagnostic; nothing has been done on the latter case - an expertise widely used in practice and not yet codified. In addition to further development of the previous work, one of objective of this study is to fill this existing gap. The paper also addresses verification - an equally important task but receiving little attention, whereby the results of interpretation are checked with all the known external data, as well as the well test data, to check for inconsistencies.

As a result, a framework of a knowledge based system (KBS) for well test design and interpretation was proposed and prototyped. It incorporates both pressure transient test data and external geological and engineering data to provide a systematic approach to designing and interpreting the well tests.

The work presented in the paper provides some guidelines in development of new generation well test interpretation software, which will have to interpret the well tests from an systematic point of view and in which the model selection and verification will be essential parts of the whole process.
Design and Performance of a Three-Phase Subsea Metering System
Authors: Dowty E. L. , Hatton G. J. , Durrett M. G. , Dean T. L. , Jiskoot R. J. J.
Published: December 2007

The development of a three phase metering system for installation on seabed templates at or near subsea wellheads is described. The Subsea Metering System (SMS) design measurement accuracies are +/− 5%. Its design pressure is 3640 psi. The design provides passive, self-regulation of the SMS over its operating range of 3000 to 18000 blpd at volumetric gas fractions of 10 to 90% and watercuts from 0 to 90%. The SMS considerably reduces capital costs of subsea field developments as it eliminates the need for (1) a separate test line from the subsea wellhead template to the platform and (2) test separator equipment on the platform.

Bulk gas and liquid separation is achieved via a unique separator concept which enables the volumetric rate of each to be measured. Commercially available vortex meters may be used to determine the bulk gas flow rate while a proprietary constriction meter is used to determine the bulk liquid rate. The watercut is measured by a Texaco Microwave Watercut Monitor1. The watercut monitor is capable of accurately determining the water fraction of oil and water emulsions and/or mixtures from 0 to 100% regardless of which fraction is continuous. A nuclear densitometer enables the amount of gas entrained in the bulk liquid stream to be determined so appropriate corrections can be made to the gas, oil and water rates.

The performance of the SMS as determined from topside tests on Texaco's Tartan Alpha Platform in the North Sea is presented in comparison with standard test separator equipment. The schedule for completing the topside tests and fitting the SMS to the Highlander Template is reviewed.
A New Fishing Equation
Authors: Schofield T. R. , Whelehan O. P. , Baruya A.
Published: December 2007

The aim of this work was to give rig site personnel a way to calculate how long to fish for stuck pipe. The paper reports on the collection of stuck pipe data, the development of a fishing equation and a means of estimating side-tracking costs.
An Overview of Horizontal Well Targets Recently Drilled in Europe
Authors: Tehrani A. D. H.
Published: December 2007

Most of the major horizontal well targets recently drilled in Denmark, France, Germany, Italy, The Netherlands, Norway and the United Kingdom are reviewed in this paper. Targets such as reservoirs containing viscous oil underlain by large aquifer, thin oil columns with large gas cap, unconsolidated sands, tight chalk reservoirs, dune sands with unknown extent and distributions, fractured reservoirs, reservoirs containing sour gases and a karstic fractured vugular reservoir are described. The reservoir features as well as some well completion data, productivities and costs are given for most. Some new data, yet unpublished, has been included for many of the examples cited. The paper demonstrates that the drilling of high angle and horizontal wells has become almost a routine operation in Europe. As the result many targets of a vast range of problems are being aimed at and successfully exploited which would otherwise not be economical to attempt with conventional wells. The petroleum reservoir engineers are therefore considering the drilling of this type of wells more seriously and in a wider scale than ever before, in their reservoir development studies.
Field Development by Hydraulic Fracturing: A High-Technology Success Story
Authors: Davies D. R. , Roodhart L. P.
Published: December 2007

The theoretical understanding and technology of hydraulic fracturing has shown tremendous progress over the last ten years. This is illustrated by the significant commitment of oil and service company research funds over this period to develop the required capabilities. Fields which were previously uneconomic are now being profitably developed, employing modern hydraulic fracturing technology. The development of this technology required input from disciplines as diverse as rock mechanics, equipment engineering and production chemistry. Shell's participation in this high technology story is illustrated by their research developments over the last ten years and the ways in which technological hurdles to applying the developments in the field have been successfully overcome.

We show how the treatment size and aggressiveness has increased over the years so as to raise well productivity. The development of unique research equipment and its impact on material selection and treatment design is described.

The understanding of the rock mechanical aspects of the fracturing process has been completely revised which, after field calibration, allows much more productive fractures to be placed. The application of this technology is illustrated by the development history of a 24-well offshore field. The high individual well production rates led to new problems with proppant back-production. The solution required a good understanding cf the process, which was achieved via a fully integrated interdisciplinary project.
Continuous Determination of Oil Pipeline Watercut, Salinity, and API Gravity Regardless of Gas Fraction: The Microwave Watercut Monitor
Authors: Marrelli J. D. , Hatton G. J. , Siddiqui F. , Pepin L. L. , Helms D. A.
Published: December 2007

The Texaco Microwave Watercut Monitor, (TMWM, STARCUT™) is a new technology currently in field applications for the continuous measurement of the percent water in crude oil production streams over the entire 0 to 100% range. The TMWM is a continuous recording watercut monitor functioning from 0 to 100 % watercut regardless of temperature, salinity, crude oil API gravity and the presence of gas. The monitor can continuously report emulsion status (water- or oil-continuous), salinity, density of the hydrocarbon phase and, in some cases, estimate gas fraction. Operator interaction is minimized by features such as automatic self-calibration, unattended operation at remote locations, remote access options through SCADA systems and self-starting after power outages. Safe operation in oilfield locations is assured by the design which has been approved as Intrinsically Safe for use in Class 1, Division 1 areas. Field and laboratory data is presented which demonstrates instrument performance over a wide variety of conditions including slug flow, free gas and salinity and crude density changes.
Auger TLP: Drilling Engineering Overview
Authors: Dupal K. , Flodberg K. D.
Published: December 2007

This paper describes the drilling engineering strategies devised for optimal development of deep reservoirs from a Tension-Leg-Platform (TLP).

Included are a summary of the TLP systems, detailed well planning, and the first year's drilling performance.
Design of a Lightweight Drillstring Using Composite Materials
Authors: Eckold G. C. , Bond E. A. , Halsey G.
Published: December 2007

The ability to drill deviated and extended reach production wells is becoming an important factor in the economic assessment of remaining oil and gas reserves. However, problems associated with the weight of conventional drillpipe, such as high torques and frictional drag, can impose severe limitations on the reach which can be achieved in the horizontal section. A lightweight drillstring manufactured from composite materials can effectively ameliorate many of these problems due to the fact that loads arising through friction can be reduced by factors in excess of 3–4. Other potential advantages include reduced rig loads, or increased rig capacity, improved chemical resistance and increased fatigue performance. For certain applications, where the horizontal leg is subjected to compressive loading, there is also scope for developing an alternative to heavyweight pipe with a resistance to buckling. This paper addresses the design of a composite drillpipe and includes consideration of mechanical and dynamic loading, environmental effects and operational factors.
Three New Systems That Prevent Firing of Perforating Guns and String Shots On or Near the Surface
Authors: Carisella J. V. , Cook R. B. , Beardmore J. E.
Published: December 2007

A new concept called Shock Block Technology has evolved in an effort to eliminate surface detonations of explosive tools. Three systems utilizing this technology have been developed. One system is intended for use in wireline hollow carrier perforating guns and jet cutters. Another system is intended for use in string shots and strip guns where the detonator and detonating cord are wetted by wellbore fluids. The remaining system is intended for use in tubing conveyed perforating guns.

Field performance data and laboratory test data is presented on three models using Shock Block Technology. Two other models are recent developments and only laboratory test data is available. Performance in the field and in the laboratory have been consistent.

Shock Block Technology is versatile. It can be used with the most commonly used detonators in the industry. It can also be used with new emerging detonator technologies.
Applications and Limitations of Horizontal Drilling in Oklahoma
Authors: Bryant J. , Watson D. , Wisniewski W. , Patterson R. , Smith L.
Published: December 2007

Focusing on case histories of recent horizontal wells in Oklahoma, this paper provides an overview of horizontal drilling activity in a region where, currently, horizontal drilling applications are still being defined. Consequently, the paper provides information — including successes and failures — of the various target applications, drilling and completion techniques, reservoir characteristics and production histories of these case history wells.

With particular focus on one of the first proposed multiwell horizontal drilling programs in the region, the paper provides specific comparisons of two different target intervals, as well as the actual drilling applications, drilling fluid types, survey techniques, and well designs. Results of the different drilling techniques are documented, including specific drilling assemblies used and production techniques employed. In addition, specific formations are documented according to their success as horizontal drilling applications.
Engineering Salary Trends in the Petroleum Industry
Authors: Lancaster D. E. , Judah J. S. , Brown D. C.
Published: December 2007

Results of the October 1990 SPE Member Salary Survey indicate an increase of about 3 to 5% in salaries received by SPE members over salaries reported in October 1989. Results of the 1991 SPE Starting Salary Survey reflect an increase in starting salaries accepted by B.S. graduates in petroleum engineering to $3,347/month. This figure is up 9.7% from a year ago and is the largest increase in starting salaries since 1982.
Sensitivity of Large-Scale Water/Oil Displacement Behavior to Fine-Scale Permeability Heterogeneity and Relative Permeabilities
Authors: Houseworth J. E.
Published: December 2007

Waterflood simulations in two-dimensional cross-sections are used to investigate the effects of fine-scale relative permeabilities and permeability heterogeneity on displacement performance. Heterogeneity is found to be most significant when deviations from the mean are highly correlated in the direction of flow, i.e., a layered reservoir. As spatial correlation decreases, the production behavior approaches that of a homogeneous medium. The critical features of the fine-scale relative permeabilities are the end-point relative permeability to water at residual oil saturation and the approach of the oil relative permeability curve to residual oil saturation. Relative permeability variations are found to be less important, but not necessarily negligible, when permeability heterogeneity is large and highly correlated in the displacement direction.

Under most circumstances, the minimum relative permeability data required to avoid gross errors in simulation predictions are the end-point effective permeabilities to each phase and the fractional flow curve approaching residual oil saturation. Waterflood simulations using exact relative permeability data are compared with simulations where complete relative permeability information is not available. Cases are considered where relative permeabilities are estimated by straight lines between known end points and relative permeabilities derived from end point measurements and fractional flow data for high water cuts. An approximate method is proposed to derive relative permeability information from limited production history data. The importance of production behavior at low fractional flow of oil also suggests the use of centrifuge measurements to help define the oil relative permeability curve approaching residual oil saturation.
Harmonization of Technical Standards
Authors: Viganego L. R.
Published: December 2007

This paper describes the formation of the European Community, the participant Countries, the Directorates within the European Commission and their functions.

It will show how the development of the "Service and Utilities" Directives together with the Public Procurement Directive promoted and initiated the Harmonisation of Technical standards within the EEC.

It will show how the programme is implemented and how the various National and International standard Bodies cooperate with CEN/CENELEC, the European Standard Organisations, to bring about an EN standard.

It will turn its attention to the Oil and Gas Industry in the North Sea and how this Operator Phillips Petroleum perceives both the advantages and disadvantages of the programme.

It is our opinion that by working together in a spirit of cooperation and understanding with the various National and European Standard Bodies, the Oil and Gas Industry can bring a wealth of knowledge and experience to bear in an innovative way, right across the wide spectrum of materials, equipment and services presently available in the Community.
Simulation of Miscible Laboratory Displacements by the Total Dispersion Method
Authors: Weisbrod K. R. , Ring W. W.
Published: December 2007

The total dispersion method was developed to simulate first-contact miscible displacements performed in the laboratory. Simulations applying this method add sufficient dispersivity to the numerical dispersion inherent in finite differencing methods so the sum approximates the actual physical dispersion. This paper describes the application of this technique to model three floods taken from the literature and three displacements performed in a CT scanner.

A key variable for modelling miscible displacements is dispersion. Numerical dispersion for both 1-point and 2-point upstream weighting was characterized as a function of grid block size and throughput for an IMPES simulator. After quantifying numerical dispersion, three floods reported in the literature were simulated to confirm the total dispersion method. Recovery curves for two displacements dominated by viscous fingering and one exhibiting gravity override were modelled with good agreement.

Our next objective was to determine if concentration profiles as well as recovery curves could be matched in a well characterized rock. First, longitudinal convective dispersion was measured for Bentheimer sandstone by a series of tritiated water displacements. Two matched density floods were performed. A unit mobility flood showed that the rock is highly uniform. The spider web pattern distributor at the inlet of the core introduced a slight bulge in the initial concentration profile.

At an adverse mobility ratio of 10, a single finger developed and moved through the center of the core. Simulation of this latter flood included the influence of the distributor and provided a good match of both recovery and concentration profiles.

A single gravity override finger developed in the final displacement. Both the total dispersion method with 2-point upstream weighting and the extrapolation method with 1-point weighting predicted the recovery curve. The total dispersion method with 2-point upstream weighting matched the concentration profile. Based upon its ability to predict concentration profiles, the total dispersion method is preferred for laboratory scale simulations.
The Decision Economics of Exploiting Seasonal Gas Markets
Authors: Lohrenz J.
Published: December 2007

Producers frustrated by low gas prices during recurrent seasonal lulls may be tempted simply to shutin or constrain production during the doldrums. This study indicates, however, that except under extraordinary circumstances, a present value maximizing operator should not fall prey to that temptation.
Gas Balancing Between Working Interest Owners: An Engineer’s Perspective
Authors: Daniel L. S. , Kelkar B. G.
Published: December 2007

Selling gas in today’s natural gas marketing environment can result in working interest owners becoming imbalanced with respect to their share of gas in a producing reservoir. To combat this, several gas balancing agreements have been written and are currently in use in the industry; however, many of these agreements fail to adequately address practical engineering problems encountered in balancing gas production. These problems include balancing of condensate production versus balancing of gas production, owner’s imbalance at the time of acquisition or sale, and nomination and allocation to pipelines and purchasers. This paper discusses these balancing problems and proposes practical solutions that can be incorporated in a standard Gas Balancing Agreement. A sample agreement is included as Appendix A.

Several types of gas imbalances, such as those between working interest owners, and pipelines and purchasers, can exist. This article only addresses the gas imbalances which occur between the working interest owners in a producing property.
Experimental Analysis, Modelling, and Interpretation of Recovery Mechanisms in Enriched-Gas Processes
Authors: Nutakki R. , Hamoodi A. N. , Li Y- K. , Nghiem L. X.
Published: December 2007

Detailed experimental data of the phase behavior of a rich gas displacing a Middle Eastern crude are given. These data include constant composition expansion, differential liberation, saturation pressure, and multiple contact PVT data as well as slim tube data at several pressures. The phase behavior of the reservoir oil / rich gas system was modelled using a cubic equation of state (EOS) with fifteen components. The critical properties of the heavy fractions, the binary interaction parameters and the volume translation parameters were adjusted by regression to match the experimental data. A good match of the experimental data was obtained. With the aid of pseudo-ternary diagrams and pressure-composition diagrams generated from the EOS the mechanism of oil recovery was interpreted as a condensing / vaporizing process with significant upper phase extraction (vaporization). The EOS fluid description was then utilized in a compositional simulator to model the experimental slim tube results. A good match of the experimental data was achieved by including the effect of interfacial tension (IFT) on relative permeabilities.

Once the primary recovery mechanisms were identified, the fifteen components were reduced to six using the technique described by Nutakki et al1. The calculations using six components were almost identical to the calculations with 15 components for both the PVT and the slim tube data.

The results clearly show that for a condensing / vaporizing process the traditional interpretation of slim tube recoveries is not valid. The break in the slim tube recovery curve with increasing pressure does not indicate multiple contact miscibility, but rather a region of reduced IFT. To model properly this behavior in a compositional simulator, the effect of interfacial tension on relative permeability must be accounted for. Because of the reduced IFT, it is possible to obtain high recovery even though the displacement process is not miscible.
A Novel Lignin-Based Surfactant System for the Salem Unit
Authors: DeBons F. E. , Whittington L. E.
Published: December 2007

Texaco conducted a successful surfactant/polymer flood in a 60-acre [24 ha] portion of the Salem Benoist reservoir in Salem, Illinois, in 1981. This pilot used a brine-tolerant petroleum sulfonate surfactant system blended in injection brine followed by a xanthan mobility control polymer in fresher water. The oil recovery over the seven year life of the flood was 487,050 bbl [77 435 m3]. This represents 45% of the oil remaining in the total thickness or 73% of that from the more permeable lower interval where most of the surfactant flowed.

Since this successful project, Texaco has continued to improve enhanced oil recovery surfactant systems. We have developed novel, brine tolerant surfactants based on the renewable resources lignin and tallow amine. This paper describes the laboratory work leading to a surfactant system which has been recommended for field testing. The laboratory work includes blending, interfacial tension measurements, and corefloods in Berea and reservoir cores.

Our novel lignin amine surfactant systems perform better in long corefloods than the field tested petroleum sulfonate system. Their costs are approximately 40% lower than the petroleum based system, and this lower cost has a major impact on project economics. The lignin amine system can be applied at a crude oil price of about $21/bbl while an equal amount of the petroleum sulfonate requires about $32/bbl for the same return on investment.

The type of lignin based surfactant system described in this report has applicability in all fields where conventional petroleum-based surfactants have been used. Their much lower cost means that they can be used economically at lower crude oil prices.