bluuebunny/crossref_metadata_2025 huggingface dataset:
A Field Study of ESP Performance in a Deep, Hot, and Sour Environment
Authors: Mohrbacher J. D.
Published: December 2007

This paper will outline procedures used to improve electric submersible pump (ESP) run lives in the Beaver Creek Madison (BCM) formation, Fremont County, Wyoming. ESP run lives increased from an average of 66 days in October, 1982, to 241 days by June, 1983. One of the seven ESPs included in this evaluation had run for 332 days by June 1, 1983, indicating run lives on the order of one year are now possible in the BCM. Discussions of installations procedures, operations and failure analysis are included. This paper also presents operating data for ESP equipment tested in the BCM, including two brands of pumps, seals, and motors; four types of downhole power cable; and a variable speed drive. Recommendations for continued improvements are also presented.
Polymer Mini-Injectivity Test: Shannon Reservoir, Naval Petroleum Reserve No. 3, Natrona County, WY
Authors: Doll T. E
Published: December 2007

The Shannon Reservoir, in the Naval Petroleum Reserve Number 3, has the greatest original-oil-in place, and the lowest projected primary recovery of the productive formations in the field. Gravity drainage controls primary production as no active water drive exists and bottom-hole pressure is low.

The Shannon Reservoir is a stratified, heterogeneous, shaly siltstone. Previous attempts at water-flooding, off the Reserve, failed due to direct communication between injector and producer. Polymer improved waterflooding was chosen for the Shannon Reservoir after extensive laboratory core analysis screening. A field test on the proposed pilot site using various concentrations of brine water and the log-inject-log technique for analysis, indicated that sufficient mobile oil was present. An off-pilot mini-injectivity field test evaluation of both a dry and a liquid polymer product system was initiated late in the Fall of 1981.

The results of the off-pilot mini-injectivity test indicated: that Shannon injection well characteristics can be changed by polymer injection; that polymer solution concentration, crosslinking and complexing can be varied for specific desired injection rates and pressures; and that resistance to flow initiated by polymer injection can be maintained with subsequent water injection.

Based on the technical evaluation of this off-pilot mini-injectivity test data, a polymer improved waterflood pilot was constructed. The pilot operation continues at this date with further comments outside the scope of this paper.
Economics and Potential for Mobility Control Methods for CO2 Floods in the Rocky Mountain Region
Authors: Pande P. K. , Heller J. P.
Published: December 2007

A levelized cost procedure is used to determine the profitability of carbon dioxide flooding in the Rocky Mountain Region for non-waterflooded fields, and of the use of thickening agents for mobility control. The effects on production of changing the mobility of the injected CO2 are estimated by use of a correlation developed by Claridge [1] from his analysis of the literature on developed five-spot patterns. The procedure shows that mobility control can be applied profitably to carbon dioxide floods. Greater profits result from operating at lower mobility ratios. The effect of varying critical operation and financial parameters on the profitability of carbon dioxide floods is investigated. The profitability of the project is highly dependent on the cost of carbon dioxide. The oil price, oil price escalation rate, carbon dioxide cost escalation rate, and discount rate for discounting future cost and revenue streams affect the profitability of the project by an order of magnitude less than the cost of carbon dioxide. However, for conventional carbon dioxide floods, carbon dioxide recycling is important and the recycling affects profits more than the parameters just mentioned previously. The cost, concentration, and escalation rates of mobility control agents are also important factors which affect the profitability of mobility controlled carbon dioxide floods. The fixed charge rate for capital and the operation and maintenance cost escalation rate affect the profitability of the flood but these parameters play a far less significant role than any of the other factors described above.
Performance and Economics of Minnelusa Polymer Floods
Authors: Mack J. C. , Duvall M. L.
Published: December 2007

The secondary recovery processes of waterflooding and polymer flooding commonly used in the Minnelusa formation are compared. Flood efficiency is improved using polymer technology. Less water is injected and less water produced to recover a barrel of oil. Flood life is shortened. Results of the Simpson Ranch polymer flood show that investment in polymer technology is profitable.
Subsea Production Control: Beryl Field
Authors: Boles B. D.
Published: December 2007

The subsea production control system installed on 3 wells in Mobil North Sea Ltd.'s Beryl Field have each logged five or more full years of service. This paper describes the control system employed and reviews the operational history.
Subsea Oil Loading System for Tankers
Authors: Sander H. H. , Sterzenbach M. , Wilke K.
Published: December 2007

The offshore oil loading systems known up to the present have many disadvantages with respect to safety and costs. Feasibility studies have therefore been carried out to examine the concept of a subsea oil loading system. This work was followed up by design of the individual components. The investigations are being carried out by DEMINEX, TNSW and AEG. This has resulted in new solutions which enable economical and reliable operations with a high utilization factor even in marginal fields and in water depths down to 200 meters. The fact that the fixed components of the loading system are located on the seabed means that application of the system is also feasible in ice hazard areas.
Newest TFL Retrievable Safety Valves for Subsea Completions
Authors: Yonker J. H.
Published: December 2007

Two new retrievable ball type safety valves are now available in the TFL (pumpdown) configuration. These valves offer greater depths in a more simplified configuration to operators planning subsea completions. They were developed at the request of major producers for use in the North Sea and Southeast Asia.

Design of these new valves began -in 1977 and early 1978 by engineers from Otis' Research and Development Department. One valve is a balance line valve with a fail-close leak protection feature. The other valve is a single line deep set valve which allows installation at greater depths than previously achieved. They have been successfully tested in test wells and test loops at the manufacturer and in two land test wells by the operators. The safety system packages for these valves are currently installed in six subsea wells – five in the North Sea and the other in the South China Sea.

The material presented in this paper shows how the capabilities of subsea production are expanded by the development of a truly fail safe balance line retrievable ball valve and a deep set single line ball valve which can be placed at or near the packer, below paraffin levels, or below the kickoff point.
The Design and Optimisation of Gravel Packing Operations in Deviated Wells
Authors: Peden J. M. , Russell J. , Oyeneyin M. B.
Published: December 2007

Gravel packing is a widely applied technique for the control of sand. The increasing application of directional drilling both on and offshore has led to a number of completion difficulties. Gravel packing in deviated wells has for a long time caused considerable difficulties especially at hole angles above 40°.

This paper discusses the development and application of a computer based prediction package utilising both theoretical principles and experimental data. The package named GRAVPACK has options available for the prediction of both annular and perforation packing efficiency for any specified set of conditions. The design of gravel packs is discussed with reference to the impact of specific wellbore parameters such as casing size, hole angle and required carrier fluid density upon packing efficiency. The sensitivity of annular packing efficiency to variable design parameters such as screen/tailpipe size, slurry flowrate, gravel concentration etc. is investigated. The packing of perforations in deviated wells is investigated with reference to perforation characteristics of length, diameter and phase angle. For the cases of annular and perforation packing comparison is made between the use of a high viScosity/concentration slurry technique and a low viscosity/concentration gravel packing system.

It is concluded that the annular packing efficiency is substantially decreased by increasing the deviation angle and increased by the use of a high density carrier fluid, and large screen and tailpipe sizes. Increases in packing efficiency sure obtained by using a higher carrier fluid viscosity although the incremental benefits decrease beyond a viscosity of 40-50 cp. In the packing of perforations in all angular phases other than the 0° (low side) volumetric packing efficiences greater than 40% are rarely obtained. The low side perforations can be effectively packed at high deviation angles although at low angles the packing efficiency is very low.

The design model has provided a useful insight into its application for gravel pack design and the clarification it provides of packing mechanisms and their dependence on individual parameters.
North Sea Stimulation Logistics and Requirements
Authors: Macadam J. M.
Published: December 2007

The development of well stimulation in the North Sea Area has provided a useful new tool for the exploration and development of offshore oil and gas. The evolution of the equipment and its demonstrated availability facilitates well stimulations through both an ease of mobilization and the capacity to undertake stimulation treatments designed for North Sea reservoirs.
Point Arguello to Use Wet-Oil Gathering System and Measurement
Authors: Poynter W. G. , Hillburn T. L. , Dubois J. D. , Williams J.
Published: December 2007

Oil production from several platforms in the Point Argeullo area offshore California will be comingled in a submarine gathering system and transported ashore through a single common carrier pipeline. Partial oil/water separation will take place on the platforms. Wet oil from production platforms, containing up to twenty percent water, will be dehydrated in one common onshore treating plant. Dry oil exiting the treating plant will be measured with custody transfer precision and allocated for both ownership and operating costs in proportion to wet oil measurements on the platforms.
The Reservoir Engineering Aspects of Horizontal Drilling
Authors: Giger F. M. , Reiss L. H. , Jourdan A. P.
Published: December 2007

Elf Aquitaine has drilled four horizontal wells in the past five years: three on land in France are part of a research and development program with the Institut Français du Pétrole; one offshore Italy where Elf is operator for an association which includes Agip.

This paper presents criteria for chosing horizontal rather than conventional wells, and gives simple analytic formulas for the productivity and water coning. Production data collected on the four wells over a period of two to four years confirms these formulas. These criteria have led us to select several new projects for horizontal drilling.
(D,T) Neutron Activation Logging
Authors: Youmans Arthur , Hopkinson Eric C. , Stewart Richard M.
Published: December 2007

The theory of activation logging with an accelerator-type neutron source as a generator of neutrons by the deuteriumtritium (D,T) reaction is briefly reviewed and the instrumentation is described which has been employed recently in tests in field wells. Factors affecting the ability of the oxygen log to identify oil in situ are discussed both from the standpoint of instrumentation requirements and. with regard to borehole conditions and operating procedures. Examples of field logging results are given and compared with the expected results based on theory and on laboratory experiments. The role of borehole fluid in the logging process is explained, and the method of determining the optimum logging speed is discussed. Recent experience with the accelerator neutron source and instrumentation for activation logging is summarized and problems relating to the future applications for this equipment are presented. New nuclear logs which can be run in conjunction with the oxygen log are described and the advantages of a 14 Mev neutron source for conventional neutron logging are explained.

Introduction

Although activation logging was first proposed nearly 20 years ago the method has been of little more than academic interest until recent years due to the instrumentation difficulties involved. Apparatus has now been developed which is capable of making logs of this type and a field test of the equipment has been underway for several months. In view of the success attained to date it is confidently expected that activation logs of commercial quality will soon become available. The present paper is intended as an introduction to the operating principles of the logging equipment and a preliminary report on the results of logging tests.

"Activation Analysis" is the term which has been used, since the development of the chain reacting pile, to denote the very sensitive analytical technique for detecting trace elements in samples by means of neutron irradiation. To analyze a sample of material by this technique it is placed in an atomic pile where it is irradiated by an intense flux of neutrons, after which it is removed and examined by various techniques to determine what "activation" was induced by the irradiation. Most of the earth's elements can be made radioactive by pile bombardment, and even very tiny quantities of certain elements may become sufficiently radioactive that their characteristic radiation, which may be beta rays, positrons, or gamma rays can often be identified with ease, particularly if the sample is dissolved and chemically separated into fractions.
Partially Penetrating Vertical Fractures: Pressure Transient Behavior of a Finite-Conductivity Fracture
Authors: Rodriguez F. , Home R. N. , Cinco-Ley H.
Published: December 2007

A semianalytical solution was developed for the transient flow behavior of a reservoir with a well intersecting a partially-penetrating vertical fracture of finite conductivity. The transient pressure behavior of a well in this kind of system consists mainly of three flow periods: 1) the early time, 2) the infinite acting and 3) the pseudoradial flow periods.

The results of this study show that the flow behavior of the partially-penetrating fracture during the early time period is equivalent to that of a totally-penetrating fracture. This period consists of a bilinear flow period for low conductivity fractures, and of a linear reservoir flow period for moderate to highly-conductive fractures.

The onset of the infinite-acting flow period is directly proportional to the square of the dimensionless fracture height, which is defined as the ratio between the fracture height and the fracture half length. The results show that as the value of this ratio becomes small, the infinite-acting flow period starts at very early times,such that the bilinear and the linear reservoir flow periods might not appear in the well response for practical values of time.

The approximate start of the pseudo-radial flow period does not depend significantly on the fracture conductivity, on the fracture penetration ratio, or on the dimensionless fracture height, for moderate to highly conductive fractures, and for fracture penetration ratios larger than about 0.2. The effect of the dimensionless fracture height on the pressure response of a partially-penetrating fractured well becomes negligible for penetration ratios larger than about 0.8.

The vertical location of the fracture affects the behavior of the well only after the upper and/or lower boundaries of the reservoir become noticeable in the pressure response of the well. The same solutions are found for the early time and for the infinite-acting flow periods, until the boundary effects become evident.
Microcomputer Finite-Element Analysis of Tubular Connections
Authors: Johnson F. W.
Published: December 2007

A user transparent computer program is described which provides finite element analysis of tubular connections. Methods of storage economizing, increasing execution speed, and improving accuracy of results are outlined. The program features convenient model creation, designation of boundary conditions, wedding the pin properly to the box, solution of linear equations, and graphical presentation of stress contours. One application is discussed comparing results to theoretical values.
A Numerical Approach to the Design of a Gravel Pack for Effective Sand Control in Deviated Wells
Authors: Peden J. M. , Russell J. , Oyeneyin M. B.
Published: December 2007

The process of gravel packing involves a substantial number of variables Which must be specified by the operator. The relationship between the variables, especially for gravel packing in highly deviated wells, is not well understood. Further, the effective packing of perforations in deviated wellbores is critical to ensuring both a productive and stable gravel packed well. This paper reports on the development of a microcomputer based package which incorporates several numerical design models as options for the design of effective gravel packing in the screen/casing annulua and inside the perforations.

Comprehensive testing of the model has indicated that the annular gravel packing process is controlled by not one but a number of parameters and thus a computer based prediction model is necessary. The packing of perforations is very difficult to accomplish with any great degree of success and is largely controlled by hole angle, perforation phasing and physical size characteristics rather than the transport controlling parameters such as viscosity, gravel size and leak off rate.
A Field Evaluation of the Mohr's Circle Technique for Predicting Sand Strength
Authors: Barrow D. C. , Lasseigne C. A.
Published: December 2007

The performance of eighteen offshore Gulf of Mexico wells was analyzed to determine whether the drawdown at which the Mohr's Circle Technique predicted formation failure corresponded to the actual drawdown at which sand production occurred. The data indicates that for this sample the technique would be helpful in deciding whether to use sand control methods in the initial completion.
Calculation of Liquid Dropout for Systems Containing Water
Authors: Lim D. , Ahmed T. H. , Striefel M. A. , Cady G. V. , Michelotti R.
Published: December 2007

Liquid drop-out calculations are presently performed without considering the presence of the water phase. The main objective of this study was to document the effect of the presence of the water phase on the liquid drop-out as predicted by the Peng-Robinson equation of state.

In addition, part of this study dealt with the study of the influence of adjusting the binary interaction coefficients between water and the hydrocarbon components on the equation of state predictions. Another part of the paper deals with the effect of changing the acentric factor and initial saturation of the water phase on the liquid drop-out predictions.
Basic Concepts in Evaluating Oil and Gas Partnerships
Authors: Boone D. M. , Cable J. O. , Archer R. L.
Published: December 2007

"Rules of thumb" have been used to make oil and gas acquisition investment decisions for many years. This paper will illustrate those factors which significantly impact certain "rules of thumb" in property evaluations, and identify potentially erroneous conclusions drawn from them. It will also discuss partnership arrangements and the affect of their structure on the promoted partner's return. In summary, a simple method is suggested to estimate property value for initial screening purposes and indicate an estimated range of return to a promoted partner.
A New Lumping Scheme of Analytical Data for Compositional Studies
Authors: Montel F. , Gouel P. L.
Published: December 2007

This paper presents a new algorithm to lump fluid compounds into hypothetical components. It has been designed to bridge the gap between the increasing amount of analytical data provided by modern lab equipments and the simplified fluid description required in compositional model studies.

The main feature of the method is a lumping scheme based on the similarities of a few proper- ties of all the compounds identified by chromato- graphic analysis. An iterative clustering algo- rithm around mobile centers yields a classifica- tion into pseudo-components optimum with respect to the considered equation of state. It can be adapted to any equation of state, any number of compounds or properties.

An other noticeable feature of this proce- dure is the definition of a mixed calculation of critical properties. A criterion to choose between an accurate calculation of true critical proper- ties and the classical mixing rules is suggested.

Numerical simulations of PVT behavior were completed for an oil and a gas condensate defined by 150 compounds. The clustering algorithm deter- mined simplified fluids lumped into 7 and 5 components. True critical properties calculation for the hypothetical components and classical mixing rules were tested and the mixed calculation proved to be the best.
Hitts Lake Unit Polymer Project
Authors: Greaves B. L. , Marshall R. N. , Thompson J. H.
Published: December 2007

Polymer injection for mobility control and sweep efficiency improvement has been ongoing in Sun's Hitts Lake Field Unit since October, 1980. The polymer augmented waterflood was implemented in stages in the four fault blocks. This paper summarizes the history of the planning, operation and results of the project to date.
Analysis of the Injection Test for a Waterflooding Experiment and Interpretation of the Accompanying Processes
Authors: Morales R. H. , Abou-Sayed A. S. , Jones A. H. , Saffar A. Al , Schmidt R. A.
Published: December 2007

A 30 day waterflooding test in which seawater was injected into two production zones (A and B) of an oil producing limestone reservoir is analyzed. During testing the flow rates were varied to maintain constant tubing head pressure. Injection rates were recorded for three levels of constant tubing head pressures (THP): initial (THP = 990 psig), intermediate (THP = 1240 psig), and final (THP = 1490 psig).

The purpose of the analysis was to detect the possible occurrence of a fracture. A radial fluid flow technique was utilized to analyze the pressure-injection behavior. The analyses disclosed a change in the formation's ability to transmit fluids. Rock mechanics analyses were utilized to quantify the changes in in situ stress due to water flooding effects (i.e. pore pressure buildup and temperature decrease). The later analysis disclosed that the bottomhole fluid pressures exceeded the modified minimum in situ stresses at the intermediate and final pressure levels.

Both, the increase in fluid transmissibility and the bottomhole fluid pressure rise above the modified minimum in situ stress indicated the occurrence of fracture. A possible fracture geometry was obtained by means of 2-D and 3-D hydraulic fracturing simulators.
A Combination of Acoustic Measurements to Evaluate Cementations
Authors: Catala G. N. , Stowe I. D. , Henry D. J.
Published: December 2007

To complement the now traditional Cement Bond Log (CBL/VDL)1, a device called CET* (Cement Evaluation Tool)2 was commercially introduced in 1982. It features an array of eight ultrasonic transducers allowing a radial inspection of the casing and its annulus. Its response can be interpreted in terms of cementation quality. In particular, distinction between acceptable cement, unset slurry or liquid, gaseous cement and free gas can be made. Analysis of the radial and vertical distribution of the materials located by the device provides the basis for the identification of possible causes of poor cementation. With these indications primary cementing procedures can be controlled and improved. Also, remedial cementing methods can be more rigorously adapted to individual situations.
Biotechnology and Enhanced Petroleum Production
Authors: Saxman D. B. , Crull A.
Published: December 2007

MEOR refers to any enhanced petroleum recovery technique utilizing single celled microorganisms or their by-products. Recent advances in microorganism screening, selective breeding, rDNA, and more productive fermentation reactors, along with a better understanding downhole environments and transport have made MEOR a more attractive alternative to more conventional EOR techniques. Recent advances and commercial; potential of six MEOR classifications are considered: 1) Bio-Production of Injected Materials; 2) Emulsification and Demulsification of Produced Hydrocarbons; 3) Desulfurization and Denitrogenation of Produced Hydrocarbons; 4) In situ Bio-Production of Polymers and Surfactants; 5) In situ Bio-Production of Miscible and Immiscible Gases; and 6) Selective Formation Plugging.
Determination of Molecular Weights and Molecular Weight Distribution of Polyacrylamides
Authors: Gregory S. D.
Published: December 2007

A high-performance, size-exclusion chromatography procedure has been developed for determining molecular weights and molecular weight distributions of polyacrylamides. The procedure can be applied to dry or emulsion polyacrylamides. Virgin polymers and polymers passed through Berea sandstone cores can be analyzed. The analytical technique utilizes a chromatographic column packed with a hydrophilic polymer resin to fractionate the polymer sample. Detection is accomplished with a refractive index or ultraviolet detector. In addition, the chromatographic system can be coupled to a low-angle, laser, light-scattering (LALLS) photometer for absolute molecular weight characterization.
The Economic Evaluation of Hull Forms for Floating Production
Authors: Hart V. A. , Montgomery J. I. , Worley M. S.
Published: December 2007

High costs and extended construction periods associated with fixed platform installations are forcing operators to look for more economic solutions to develop marginal offshore fields. A Floating Production System (FPS) provides a viable development alternative for smaller fields, especially in deeper waters. However, the available floating production system alternatives differ considerably in cost, construction time and capability. An identification of these differences and a method for preliminary economic assessment will provide operators with reference points when evaluating new field development schemes.
The Role of Potassium in Lime Muds
Authors: Walker Thad O. , Dearing Harry L. , Simpson Jay P.
Published: December 2007

Laboratory data are presented showing that lime muds utilizing a polysaccharide deflocculant are very effective in combating dispersion of shale particles when compared to several commonly used types of water based muds. Similar studies using Wyoming bentonite particles are reported snowing that potassium hydroxide results in less clay dispersion than sodium hydroxide when used for alkalinity control of a lime mud deflocculated with polysaccharide. While the potassium is shown to be reactive with clay particles, the presence of lime in the mud leaves more potassium ion available to react with shale exposed in the wellbore and protect against borehole instability.

Field results are reported showing that potassium ion concentrations of 1,000 to 4,000 mg/L have been adequate in potassium/lime muds containing polysaccharide deflocculant to provide good borehole stability and low mud maintenance costs.
A Stability Theory for Miscible Displacement
Authors: Peters E. J. , Broman W. H. , Broman J. A.
Published: December 2007

This paper presents a dimensionless stability number and its critical value for predicting the onset of instability in miscible displacements. Also presented is a novel technique for determining the dispersion parameter required for calculating the stability number. The technique combines spectral analysis with computer image processing of the solvent fingering pattern.
Cement Shrinkage and Elasticity: A New Approach for a Good Zonal Isolation
Authors: Parcevaux P. A. , SauIt P. H.
Published: December 2007

Characterization of cement bonding performance required the set up of new pieces of laboratory equipment. The evaluation of cement bonding property has been performed under controlled temperature and pressure curing conditions, and was proved to be reproducible with a very small dispersion of results. Shear bond has been tested through mechanical and hydraulic means, and related to other parameters such as volumetric shrinkage development, stress-strain relationships, permeability, and compressive strength. A laboratory and field experimental program has been conducted to compare the bonding capability of standard cement compositions with that of cement modified with a bonding agent. Laboratory and field results are in perfect accordance.
How To Think About Energy Prices
Authors: Tussing A. R.
Published: December 2007

Oil-price surges in the 1970s were not harbingers of ultimate resource depletion, but only a severe manifestation of a commodity-price cycle. Another round of excess supply and falling prices was thus inevitable. Thus far, history does not show any unambiguous long-term trend in global petroleum-production costs, but there is an inexorable tendency for energy cost to fall, whatever the limits may be to supplies of specific fuels.
Some New Ideas for Well Log Pore-Pressure Prediction
Authors: Hamouz M. A. , Mueller S. L.
Published: December 2007

Predicting pore pressure from wireline logs is a common practice when designing wells. The accuracy of each prediction depends on the type of plot used and its associated assumptions. If these assumptions aren't adequately tested, then the results are often confusing and, possibly, dangerous.

Accuracy is improved in all situations by plotting the correct wireline variables, checking the validity of the normal pressure trends with other pressure plots and regional data, and choosing the best techniques to estimate pressure.
A Stimulation-Sand Control Method
Authors: van Poollen H.K. , Malone W.T.
Published: December 2007

The authors have suggested explanations for the occurrence of sand problems, which include stresses due to drilling, initial formation stresses, and formation fluid pressures. These stresses combined result in rock failure immediately adjacent to the wellbore. This, in turn, leads to a plastic or semi-plastic state of stress, which will cause rock to flow into the wellbore due to mechanical stresses. In addition to the mechanical stresses, those developed due to viscous drag tend to move formation particles into the wellbore.

The authors suggest a possible explanation of wellbore damage peculiar to sand problem wells.

Two methods of sand control are briefly described. In the first method, a sheath of sand is formed adjacent to the wellbore serving as a screen for particles moving toward the wellbore, and a bridge over the performations or liner slots. The second method includes the creation of lenses or fractures prior to placing the sheath. These lenses or fractures are believed to be formed by high rates of injection due to the dilatant characteristics of sand problem formations.

From a production standpoint, the particle size in the sheath or pack is of no importance as References and illustrations at end of paper long as it has a higher permeability than the formation. It would appear, therefore, that the size of the packing sand should only need to be determined by its bridging and screening capacity. Both methods result in stimulation of a well; however, it is pointed out that the method using both fracturing and packing appears definitely superior.

Introduction

In certain areas, particularly in the Gulf Coast and California, formation sand is produced with the oil. The amounts of sand produced cause both production and disposal problems.

To keep the formation sand in place, graded sand is frequently pumped into the wells and packed behind the casing, a liner or a screen. As much as 97,000 lb of sand have been used in a single treatment. The sand is pumped into the well in a fracturing fluid in concentrations of about 2 lb/gal. The process of sand packing dramatizes the possible existence of a plastic or semi-plastic ring surrounding the wellbore.

Two main methods have been used for the placement of the packing sand. One method assumes that the unconsolidated formation will compact or compress and allow the packing sand to build in concentration immediately adjacent to the wellbore. Usually pressures are not allowed to increase rapidly throughout the process.
A Strong Transfer Function Links Thin-Section Data to Reservoir Physics
Authors: Ehrlich R. , Horkowitz K. O.
Published: December 2007

Petrographic thin sections carry considerable precise quantitative information concerning physical properties including permability, log response and acoustic phenomena. This information is not carried by conventional pétrographie procedures such as point-counting or simple linear measurements made with a graduated ocular. Instead, multispectral image analysis techniques are required. Critical parameters of such a system include: 1) selection of correct magnification; 2) selection of proper spectral bands; 3) construction of a high precision digital filter able to precisely define grain and pore boundaries at the upper surface of the section; 4) an algorithm to express in useful fashion the complex geometries of grain and pore as well as correctly identify minerals and mineral phases; and 5) software to analyze such data. Output data is copious -- for example, over 300 variables describe estimation of such properties as permeability and identification of pore characteristics associated with enhanced or reduced permeability.
Price Forecast for Energy Lending
Authors: David A. , Carson G. P.
Published: December 2007

The movement of world oil prices continues to be a topic of interest and concern. While political forces are a factor in price projections, banks primarily use the long term oil supply and demand situation as the underlying support for making oil and gas price projections.

Last year, price fluctuations and the uncertainty associated with price forecasts caused banks to follow their lending policies more closely and to become more prudent in their lending guidelines by assigning more risk to nonrevenue producing reserve categories. However, the ability of banks to lend against collateral composed of oil and gas reserves has not decreased.

Thirty energy banks were surveyed to determine how they assign loan values and to compare their pricing and loan assumptions. The most notable change from last year's survey is that most banks have lowered their price escalation projections. Although the banks' lending policies for proved producing reserves remain similar to previous years, uncertainty regarding future prices and its associated risks for nonproducing and undeveloped properties increased.

This paper compares the banks' pricing assumptions, and shows how price variations can have dramatic effects on loan value. This paper also compares the 1983 survey results with the previous two years.
Paraffin Inhibition Treatments Reduce Well Maintenance Costs
Authors: Charles J. G.
Published: December 2007

In many oil producing areas, paraffin deposition on downhole tubulars can present serious production problems. There are currently many methods available with which to try and solve or lessen the severity of these problems. Although it seems no one solution has a very large area or number of wells with which it remains efficient. A new patented process now has the ability to treat wells in many different areas and formations, and yield excellent results. This apparently universal application can save long periods of trial-and-error testing in an attempt to find a solution to each well's specific paraffin problem.
New Stimulation Technique Improves Frac Recovery and Increases Production
Authors: Phillips A. M. , Wilson W. J.
Published: December 2007

A technique for improving stimulation fluid recovery has been developed in the laboratory and has proven effective in field applications. The method involves improving proppant pack drainage and minimizing capillary pressure in the formation through the judicious application of surface active agents.

The technique is particularly applicable in low pressure oil wells and tight gas reservoirs, and may be used in all aqueous fracturing treatments. These include slick and gelled water, as well as foamed and crosslinked systems. The technique involves the use of a solvent in the pad fluids and a surfactant system throughout the entire fracturing treatment. This combination improves sand pack drainage and minimizes capillary water blocks in the invaded formation, while maintaining the water-wet condition of both the proppant pack and formation.

The results of field applications using this technique have shown great improvement in the recovery of aqueous stimulation fluids in both sand and limestone formations. Increases in initial hydrocarbon production have also resulted. Case histories are presented from both oil and gas wells in a variety of formations.
Simplified Approach to Air Drilling Operations
Authors: Puon P. S. , Ameri S.
Published: December 2007

Traditionally, air requirements during an air drilling operation involve the utilization of the Angel's chart(s). The values from the mentioned chart(s) are generally 20-25% below the acutal field's requirements/needs. Recent studies in this area have provided more reliable results, however, the tedious calculations, the lack of proper charts, and the absence of the user-friendly programs have prevented their practical applications. The authors of this paper have developed a simplified model that takes into account both the material balance and momentum balance for the annulus. Air and cuttings have been treated independently in these balances. Multiphase momentum balance equation is adopted. This model will also accommodate the air lifting capacity in the annulus to be the dominant factor in deciding the air requirements.
The Operator-Contractor Relationship—Gains and Losses, 1982 to 1984
Authors: Chiles W. E.
Published: December 2007

Q. Have drilling costs decreased? How was this obtained – better efficiency or price cuts? A. Since we are in the offshore drilling business I can only speak in terms of the offshore industry. Drilling costs for the offshore operators have decreased approximately 35-45% since January, 1982 when utilization rates and dayrates began to fall significantly which continued until September, 1983. Although a large part of the decrease in costs can be traced directly to price reductions in all goods and services used in drilling, some of the reductions have been as a result of better efficiency on the part of drilling contractors, operators, and other service companies. Turnover is way down and we've had time to do a better job of training our personnel. In fact, during these lean years, we have appreciably increased our training budget to take advantage of this situation so that we will be in a better position when we start graving again. I think that we can all say that we have much more qualified personnel offshore today than ever before. Drug usage seems to be down also. Q. Has productivity improved? Where did it come from – the operator, the contractor, or both parties working together? A. As stated above, efficiency has improved across the board, and this is largely due to better qualified and trained personnel. However, operators and contractors are finally learning that their relationship is not an adversary one and that teamwork is the key to getting a well drilled in the least amount of time at the lowest cost. For years, we've had a situation offshore where there was a continuing battle over who was going to be on top of the heap – the operator's representative or the contractor's toolpusher. Egos were the important thing and the well would get drilled anyway. This situation could not be tolerated and is gradually changing by better training in basic supervision and management. Everyone is finally realizing that we are all cut there for the same reason – to safely drill and/or complete a well in the least possible time and cost. Once this objective has been established and is clear in everyone's mind, the next step is total cooperation and teamwork from the planning stage all the way through moving the rig off location. Q. What has been the effect of price cuts on quality of service, downtime, maintenance, safety and training? A. I can only speak about our company. We have not reduced our level of service one bit. In fact, we feel that it has never been better. Our crews are better, our rigs are in the best shape ever, and our safety record has improved significantly. We made a commitment when the downturn hit to cut costs only in areas that would not affect our level of service nor would cost us dearly down the road.
The Operator-Contractor Relationship—Gains and Losses, 1982 to 1984
Authors: Johnston R. E.
Published: December 2007

The boom and bust days of the period between 1979 and 1983 was a very painful period for the Oil and Gas Industry. A mania seemed to grip the entire industry! The feeling was that the boom was here to stay, would last forever, and tomorrow would never come. Unfortunately, this thinking and prevailing outlook brought about many unfortunate situations. Operators felt that with oil and gas bringing premium prices, unusually high lease costs were economically justifiable as well as inordinate high drilling costs and elevated equipment costs. In the thinking of most operators nearly every lease had to be drilled as quickly as possible, and if production was established the wells had to be placed on production with an absolute minimum of delay.

Then the "bust" came. Led by the Penn Square Bank debacle and later the natural gas pricing turning soft, activity hit bottom in an almost unbelievable short period of time! Suddenly the industry was faced with a giant oversupply of drilling rigs, service companies, and equipment.
Jackup Rig Designs for Environmentally Sensitive Areas
Authors: Chiles W. E. , Cochran T. J.
Published: December 2007

As the search for oil and gas moves into more environmentally sensitive areas, and State and Federal regulations with respect to waste discharges are becoming more restrictive, it is imperative that offshore drilling contractors design and build drilling units fully capable of meeting the most stringent regulations. All operating parameters must be examined so that any potential source of pollution or waste discharge has been identified and prevented, including, in certain instances, the collection and safe discharge of rainwater runoff. The systems designed to accomplish the above must be cost effective, simple, and must not adversely affect the drilling operation.
Elastic Yield of Casing Due to Elevator/Spider System
Authors: Hayatdavoudi A.
Published: December 2007

Through many simulated experiments, it has been found that the casing will yield prior to its being run in the hole. The yield is generally due to the high radial and friction side loads imparted to the casing by slips in the spider/elevator system. In order to reduce the occurrence of high magnitude of the hoop strain and possibly the yield of the pipe, the stiffness of the inserts has been changed by incorporating an "insert backing" material into the slip system. This reduces stored energy into the pipe. Furthermore, the optimum FRIMB load (Friction and Imbedment Load) per tooth of inserts and the insert tooth spacing have been found. In order to facilitate the analytical solution of cylindrical shells, a much-needed function previously not available has been generated experimentally.
Invert Oil Mud Rheology as a Function of Temperature and Pressure
Authors: Politte M. D.
Published: December 2007

There is a need in the drilling industry to be able to predict the viscosity of oil muds as a function of temperature and pressure. This paper presents the results of an experimental investigation into invert diesel oil emulsion mud viscosity and how it is affected by downhole conditions. Results are given from tests on diesel oil, brine, low colloid oil-brine emulsions, and low colloid muds ranging in density from 10-18 ppg.

It was found that invert oil muds generally behave like Bingham plastics. The plastic viscosity can be normalized with the viscosity of the continuous phase, and can therefore be predicted as a function of temperature and pressure. The yield value is only weakly affected by pressure, while the temperature dependence depends upon the amount of solids and organophillic clay present, and the temperature/shear history. A method is given to estimate downhole plastic viscosity and yield value based upon surface measured values.

Results of example calculations are given which show that the use of variable plastic viscosity in friction pressure loss calculations makes little difference in most cases, and that the calculations are not very dependent upon the base oil used, whether diesel or one of the less toxic oils.
Drilling Performance: The Struggle to Improve
Authors: Hough R. B. , Coumans H.
Published: December 2007

During the past three years, an intensive exercise has been underway in Shell Expro to improve the drilling performance in its fields Brent, Cormorant, Dunlin and Fulmar, and on mobile rigs. Expro approached this by concentrating on its primary resources: Men, Materials and Methods. The emphasis has been on trying to improve motivation, committment and knowledge by all involved in the operation, to try out new techniques and equipment where such are identified as being potentially beneficial, and to study procedures currently in use, with the object of improving the drilling efficiency.
Planning, Drilling, and Evaluating a Deep Wildcat in North Central Louisiana: A Case History
Authors: Scott D. G. , Dwiggins R. , Lynch K. W.
Published: December 2007

ARCO Oil and Gas Company and ARCO Exploration Company recently drilled and evaluated a 17,532 ft. wildcat twelve miles south of Natchitoches, Louisiana. This paper is a case history discussing the planning, drilling and evaluation of this well.

The planned stratigraphic selection of casing points proved vital to the elimination of lost circulation and was the key to the relatively trouble free drilling of the well. Rig selection, with emphasis on good bit hydraulics, resulted in penetration rates with 12 1/4 in. bits that equaled or exceeded those of the smaller bits used in offset wells. A low colloid, high temperature stabilizer mud system performed well in the presence of CO2 contamination at a bottom hole temperature above 400° F.

The well was evaluated in production casing with the rig in place using rented tubing, a retrievable packer, and a surface drill stem test manifold. Reservoir content was determined at a reduced capital cost. The stimulation and well control limitations of this assembly are discussed.
Measuring the Wear of Milled Tooth Bits Using MWD Torque and Weight-on-Bit
Authors: Burgess T. M. , Lesso W. G.
Published: December 2007

A bit torque relationship based on a force balance concept has been proposed by Warren1. The relationship shows that for a given bit, the torque is determined by the applied weight-on-bit and the depth of tooth penetration. This paper extends the torque model for soft formation milled tooth bits to show how the effects of tooth wear can be taken into account. The method is intended for formations like shales that are drilled by a gouging and scraping action.

An interpretation technique, based on the model, is developed. It is called the Mechanical Efficiency Log (MEL)TM. It uses time averaged values of penetration rate, rotation speed, and measurements while drilling (MWD) values of torque and weight-on-bit. The result of the interpretation is real time calculations of tooth wear, drilling efficiency, and the in situ shear strength of the rock.