bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation Evaluation in Heavy Oil Sands
Authors: Brown James S.
Published: March 2010

"Formation evaluation" comprises correlation, reservoir detection and reservoir evaluation. In the Chauvin, Wainwright and Lloydminster areas, the principal heavy oil reservoir is the Sparky sand. The oil sand pools are surrounded by halos or "channels" of shale. Correlation is more difficult inthe Lloydminster area than in the Wainwright area or the Chauvin area because the sand distribution is more complex. Reservoir detection is more difficult at Wainwright and Chauvin because the oil sands are thin and apparent resistivities are low; at Lloydminster, the oil sands are thick and apparentresistivities are high. At Wainwright and Chauvin, a resistivity log, aporosity log and often a drill stem test are necessary for a decision to setpipe; at Lloydminster, all that is required is an electrical log. Productivityvaries considerably from pool to pool, probably because of changes in sandpermeability and oil viscosity. As these changes cannot be detected by theelectrical log prior to setting pipe, the present practice is to determineproductivity by production testing after setting pipe. Transmissibility,(kh/u), as derived from drill-stem test data, may provide a means of estimating productivity prior to setting pipe.

Introduction

The techniques used for formation evaluation vary from area to area, as each area has problems which are peculiar to it. The purpose of this paper is todiscuss some of the problems peculiar to the heavy oil reservoirs of the Lloydminster, Chauvin and Wainright areas, and to mention certain techniqueswhich provide the necessary data simply and economically. In the following, the Lloydminster area will be discussed first; this will be followed by adiscussion of the Wainwright and Chauvin areas. The geology of each area willbe commented on, but only insofar as it bears on the problem of correlation andreservoir identification.
Principles of Heavy Oil Recovery
Authors: Szasz S.E. , Thomas G.W.
Published: March 2010

Rising exploration costs have prompted greater interest in the large knowndeposits of heavy oil on our continent. Because of high oil viscosities in suchreservoirs, recoveries are poor, fluid drives are inefficient and productionrates are uneconomical. Viscosity reduction can best be accomplished by heatingthe reservoir. The basic aspects of reservoir heating are reviewed and thoseprocesses which are of practical importance in heavy oil reservoirs arediscussed.

Wellbore heating frequently can be applied to heavy oil reservoirs toincrease production rates. It will only be effective, however, where some reservoir driving energy exists and sanding problems are not severe. Forward and reverse combustion usually require so much air in heavy oil reservoirs thatthese processes are uneconomical. In hot water flooding, the water requirementsare much higher than in an ordinary waterflood. Steam floods are more attractive, but operating costs are generally high. Fresh water condensate fromthe steam may also cause severe reservoir damage.

Conduction heating processes appear most promising. Among these we includethe cyclic steam-soak process. A simple method is presented for estimating the performance from the first cycle of steam injection into the formation, assuming gravity as the only driving energy.

An example calculation for a typical heavy oil reservoir is given. Theresults yield conservative estimates. The combustion-conduction process is attractive because of the characteristic low air-oil ratios. The productionperformance of the heated reservoir is not readily predicted, however. Fracture heating processes hold great promise, provided that we can develop means forcreating fractures with controlled orientation and direction.

Introduction

The cost of finding new oil reserves has been rising continuously over thepast two decades. The oil industry has therefore put increasing emphasis onimproving recovery from known reservoirs. Recently, attention has been directedto the large deposits of heavy oil on our continent. The U.S. Bureau of Mineshas estimated (1) that in the United States there are more than 150 billionbarrels of oil with a gravity of less than 25°API in known reservoirs. Most ofthem contain more than 1000 bbl/a.ft.; about half of them are at depths of lessthan 3000 ft. Oil recovery from these reservoirs, however, is estimated at 11per cent, compared to an estimated ultimate recovery of 30 per cent fromconventional reservoirs. This makes heavy oil reservoirs especially attractivedespite their low oil mobilities.
Steam Simulation for Secondary Recovery
Authors: Owens W.D. , Suter Vane E.
Published: March 2010

This paper describes the steam stimulation process, and discusses where itis applicable, and why it succeeds and fails. Field data for three separateprojects in California are presented. Oil recovery from a single cycle ofinjection and production is discussed and a theoretical method of calculatingoil recovery is shown with an example. The major components of steamstimulation costs are listed. A generalized correlation of reservoir oilviscosity versus temperature is presented in a form convenient for use in steamstimulation work.

Introduction

Steam stimulation has caught the fancy of the petroleum industry. The ideais not new, because the effect of temperature on crude oil viscosity has beenknown since the days of Colonel Drake. Early-day patents concerned theinjection of steam to reduce viscosity and clean up paraffin deposits aroundthe wellbore.

There has been a cloak of secrecy surrounding steam stimulation activities, motivated by the hope of acquiring producing properties susceptible to thesteam stimulation technique. Many of the reasons for secrecy are now gone. As amatter of fact, many of the sellers have a fear of missing out on something andare asking prices that may be over and above the actual worth of theproperty.

It is important that the oil industry break through the darkness andmysticism surrounding steam stimulation. This paper is presented as an encouragement to others to publish and exchange information, and to put steamstimulation in its rightful place as a valuable means of improving the recoveryand profitability of our more viscous oils.

What Is Steam Stimulation?

Steam stimulation is the addition of thermal energy to a reservoir by steam injection. The same well is used for injection and production. The primary object of the steam injection is to get heat to the bottom of the hole andlower oil viscosity. The rock at the bottom of the well acts as a heatexchanger and permits storage of heat from the injection cycle, to be usedeffectively as the oil is produced back into the well.
The Pipeline Transportation of Heavy Oils
Authors: Moreau B.L.
Published: March 2010

Heavy oils tend to be highly viscous. The excessive pressure gradientscaused by high viscosity have discouraged the development of heavy oilpipelines in Western Canada. This paper reviews briefly and comments on some ofthe methods used to overcome this difficulty.

The crude may be heated to reduce viscosity. This method is well known, andtemperature profiles along a hot oil pipeline may be calculated by an equation given in the paper. There is some difficulty, however, in accurately predictingheat transfer rates because of unknowns in soil temperature andconductivity.

Blending the viscous crude with a diluent to reduce its viscosity isprobably the simplest method of obtaining pipeline access to interprovincialmarkets. If a light diluent such as natural gasoline is used, even small percentages greatly reduce the viscosity. Although there are methods ofestimating the viscosity of a blend from a knowledge of the viscosity of the components, laboratory tests on the actual blends to be transported margin moredependable information.

The addition of water to viscous oil lines is known to reduce pressuregradients, and research on this matter has been conducted by several people, including the Alberta Research Council. This method, however, may have certain operating difficulties and more work on the matter, would he helpful.

The designer of heavy oil pipelines is advised to give careful consideration to all the alternatives and make detailed studies before deciding on the methodto be used.

The paper outlines briefly some of the design features of Husky Pipeline Ltd.'s Lloydminster to Hardisty system, which went into operation late in 1963.This 6 5/8-in. pipeline, 72 miles long, utilizes three pumping stations tohandle a blend of Lloydminster crude and natural gasoline. The pumpage isheated to 130°F at each station. A fourth pumping station at the outlet end(Hardisty) allows pumping in either direction; the reversal is used to batchthe diluent north to the crude source, where it is blended with the Lloydminster crude. The blend pumping rate is 15,000 bbls/day.
Optimizing Profitability of a Dual-Zone Alberta Gas Field
Authors: Nicholls R.G. , Kloepver C.V.
Published: March 2010

A comprehensive data-gathering program conducted concurrently with reservoirdelineation at East Crossfield resulted in the early definition of the physicalproperties of this dual-zone gas field. Based upon this data, it was possibleto ascertain the exploitation alternates (field development, gatheringrequirements, process facilities, etc.) available to the owners. Once thesealternates were defined and evaluated, it was possible to concentrate effortsto cause implementation of those factors which would contribute to therealization of maximum recovery and optimized profits. Gas sales from East Crossfield commenced only four and one-half years after discovery. The successof the engineering effort is reflected in the enlightened provisions of theunitization and gas purchase agreements, and in the unique exploitation planadopted. The economic gain to be achieved for this project demonstrates thevalue of this approach to oil and gas field management.

Introduction

In September of 1960, the East Crossfield Mississippian and Devonian gasreservoirs were discovered with the successful completion of a well, Pan Am Fargo G-1 Cross, located in Lsd. 16-14-28-1 W5M. Since that time, a total ofeleven wells have been drilled in the field, of which four are dual-zoneproducers and six are productive from only one zone. In total, there are sevenpotentially productive Elkton wells and seven potentially productive D-l wells.The one non-productive well, Pan Am Fargo Q-l, is being used for the disposalof produced water. For a general orientation of the East Crossfield area, referto Figure 1.

Throughout the period of development drilling, an engineered approach todata gathering was practised and, by late 1962, the field properties weresufficiently well defined to warrant the commencement of negotiations for gascontracts and for the formation of a Unit. Those properties established werebottom hole pressure, AOF and deliverability characteristics, hydrocarbonproperties, flash behaviour, etc. The gas contracts, which were executed bymid-1963, provided for a gas sales delivery date of November 1, 1964. Followingthis, there was a short delay in the project development occasioned by thedelay in obtaining the necessary governmental gas export approvals. Coincidentwith obtaining this approval, the plant construction contract was awarded.Unitization became effective on March 1, 1964, and gas sales commenced aboutone year later, on February 14, 1965, only four and one-half years after thefirst discovery well was completed. It is the purpose of this paper to reviewthe positive actions taken by the owners of this field which will result in anoptimized project profitability.
Applications of the Delta II Dynamometer Technique
Authors: Eickmeier J.R.
Published: March 2010

The Delta II Dynamometer Technique provides a diagnostic method of evaluating downhole pumping performance. Surface dynamo meter cards are analyzed by computer to determine load displacement conditions at the pump and at intermediate points in the sucker rod string. The pump dynagraph card generated by the computer program permits a complete analysis of downhole pumping conditions. Pump intake pressures can be calculated from the pump dynagraph cards. A study of pump intake pressures at varying production rates and/or at different cumulative production provides essential information on well performance. Load conditions occurring at the top of each rod string taper can be examined to determine maximum rod stresses and stress ranges. Rod strings can be altered to obtain balanced rod string loading where it is evident that designs are not satisfactory.

Introduction

The Delta II Dynamometer is being used in production operations in the U.S.A. and Canada. Shell Canada first utilized the instrument in October, 1963.Since that time, approximately 800 cards have been obtained from more than 300 pumping wells in Western Canada and the instrument has become indispensable toproduction operation. The Delta II Dynamometer Technique provides a diagnostic method of evaluating downhole pumping performance. With conventionally obtained dynamometer cards, only a qualitative and somewhat dubious interpretation of pumping conditions can be inferred from visual inspection of the surface cards.With the Delta II Dynamometer Technique, however, the pump dynagraph card is calculated by computer analysis of the surface dynamometer card. The pumpdynagraph card accurately describes the downhole pumping conditions.Intermediate sucker rod stresses are also generated by the program. In essence, through the use of a mathematical solution of the sucker rod pumping system, the measured surface loads are "decoded" to determine the downhole loads.
Determination of Natural Gas Recovery Factors
Authors: Stoian E. , Telford A.S.
Published: March 2010

Theoretical and statistical methods of determining recovery factors ofsolution, associated and non-associated natural gas, including gas condensate, are presented as a set of practical tools.

The effects of recovery mechanisms and pool and gas-well performance on gasrecovery are examined for conditions applying to constant volume, water drive, gravity segregation and secondary recovery. Ways of recognizing such cases areindicated.

The supporting techniques comprise material balance calculations, performance predictions and statistical analyses of depleted pool and predictedrecovery data. In material balance calculations, the gas recovery is consideredin terms of either:initial gas in place multiplied by a recovery factor orinitial gas in place less the gas remaining at abandonment.

Performance predictions are based on geological, engineering and economic factors. The background study dealt with explicit correlations between:recovery factor, abandonment pressure or related expressions and pool depth, pay thickness, initial reservoir pressure, flow capacity and size of gas accumulation; andequivalent residual gas saturation and formation water saturation, porosity, permeability and specific surface area.

The format for several correlationspresented is predetermined by theoretical considerations. Existing short-cutmethods are also evaluated. Easy-to-use approximations readily yield reliableestimations despite their simplicity and can be of considerable significance;however, the practicing engineer is urged to recognize and understand their limitations.

An extensive review of methods of determining recovery and an analysis ofmany evaluations by industry form the foundation for the recommended guidelinesto serve the engineer. The methods of determining recovery factors areconsidered according to their practicality; i.e. the availability ofdata and the complexity of implementation. Useful relationships are classified, important steps of the proposed procedures are outlined and severalapplications are illustrated.
Interpretation, Averaging and Use of the Basic Geological-Engineering Data
Authors: Havlena D.
Published: March 2010

The purpose of this paper is to emphasize that the taking, assembling andaveraging of the basic data for further use in an analysis of a reservoirrequires a profound knowledge of many of the specialized disciplines of moderngeology and petroleum engineering. The various aspects of " Static Data," aspresented in this paper, analyze that problem and specifically discuss the following major subheadings:Porosity,Permeability,Facies Mapping,Connate Water,Relative Permeabilities and Capillary Pressures, andMethod of Least Squares.

This paper is essentially a generaland philosophical discussion on the necessity for obtaining data quality and ofthe need for an integrated approach to be applied in a detailed analysis of anyreservoir.

Introduction and Objectives

The correct taking, interpretation and usage of reservoir data are among themost important tasks of the petroleum engineer, and particularly of thereservoir engineer and geologist. On the quality, and to a much lesser degreeon the quantity, of this information depends the success as well as theaccuracy of all the subsequent geological and engineering studies and finallyof the economic evaluations. Despite this paramount importance, very little isfound on this subject either in petroleum literature or in universitycurricula. There are exceptions - e.g., the normal types of pressure build-upcurves and the determination of the areal and volumetric average pressures, without explaining when to use which and why. At the present stage of knowledgeof the science of reservoir physics, it appears that the analytical methods ofsolution (equations) are normally, from a mathematical and physical standpoint, much more exact than the basic data and particularly the averages which are fedinto them. In layman's terms, the reservoir analyst often performs an exactmultiplication of doubtfully reliable numbers. This lack of interest in theaccuracy and representativeness of the basic data and in the methods ofaveraging them is usually explained by the simplicity of this problem, whichcan be solved by " common engineering sense;" this explanation is correct if itis backed by a thorough and uniform theoretical, as well as practical, understanding of this complex problem.
Visual Path Analysis A Qualitative Technique for Operations Planning
Authors: Schoemaker Richard P.
Published: March 2010

Advanced planning techniques have been proven as a very effective andinexpensive means to maximize the use of manpower and resources. An importantcontribution toward improved planning has been made by the technique known as Critical Path Analysis. However, the effective use of this quantitativetechnique is severely limited in many sectors of operation in the oil industry, due to the great element of uncertainty. Nevertheless, the quality ofperformance in these sectors of operation would benefit greatly from aconsistent and systematic logic in planning. In the absence of a meaningfultime-dollar definition of all elements of a project, or operation, the planningeffort should be directed toward the qualitative definition of the projectstructure.

A qualitative technique for operations planning is formalized in this paperand has been used with good results in a great variety of projects. The essenceof this technique is to stimulate organized thinking and to portray theorganized thought in a diagram for further examination, communication andexecution. The diagram shows the entire structure of the project, orplan of action, in its main divisions, subsidiary components, as well as areasof uncertainty, requiring further definition.

The technique is called Visual Path Analysis, because the diagram portraysthe path of the train of thought in exercising qualitative judgment andanalyzing the project logic. The technique can be used for the planningof a simple operation, or a highly complex project, as well as for planning inthe face of uncertainty. The method provides an effective medium for rapidcommunication of ideas to associates, supervisors and management. The diagramis useful for information retrieval and for preserving the continuity ofplanning and work in progress when a key individual is transferred to otherduties, or leaves the organization.

The technique is relatively uncomplicated, but, because of its simplicityand the absence of rigid rules, requires practice and some natural aptitude toachieve effective diagramming.
Sour Gas Compression at the Whitecourt Plant
Authors: Baraniuk E.M.
Published: March 2010

The West Whitecourt Plant uses 12,500 Bhp for the compression of sournatural gases containing 25 to 50 percent H,S. Compression ratios range from 2.4 to 4.6, suction pressures from 400 to 1,800 psig, and discharge pressuresfrom 1,800 to 4,000 psig. This sour gas has been successfully handled for thepast five years. Numerous problems related to valves, piston rings, rodpacking, piston rods, cylinders and the selection of lubricants have beenencountered and solved. The solutions to these problems were dependent upongood material selection in the case of packing and rings, and special metallurgical requirements for pistons, piston rods and valves. Special operating techniques and good preventive maintenance practices, incorporating proper material selection, lubrication and metallurgical requirements, haveresulted in a high degree of compressor dependability.

INTRODUCTION

THE WEST WHITECOURT PLANT COMPRESSOR STATION is located in the Windfall gasfield, 26 miles west of the town of Whitecourt, Alberta. The compressor stationand gas processing plant are operated by Pan American Petroleum Corporation onbehalf of itself, Hudson's Bay Oil and Gas Company Limited and Canadian Fina Oil Limited. The compressor plant is primarily employed to inject sour gas fromthe Pine TO AMINE UNIT SALES Creek and Beaver Creek gas fields into the Windfall reservoir for cycling and pressure maintenance. De- hydrated gas from the Pine Creek and the Beaver Creek fields., located 25 miles southeast of the West Whitecourt plant, is transported through a 14-in., 25-mile pipeline. Injection commenced in April, 1962, and will continue until approximately 1975. The compressors will then be utilized as boosters during blowdown of the Windfall reservoir.
Combination Drive Predictions by the Muskat and Differential Tracy Material Balances Using Various Empirical Relations and Theoretical Saturation Equations
Authors: Sandrea R. , Nielsen R.F.
Published: March 2010

Combination drive predictions by material balances require a water invasionlaw, some assumption regarding pressure decline or production rates, and asaturation equation for that part of the original reservoir which governsgas-oil ratios (unless the latter are assumed at fixed values), in addition tothe material balance. One form of the latter is the Muskat equation, which contains pressure derivatives of the volumetric fluid properties and water encroachment, the two main variables being pressure and average saturation overthe original oil zone. Another is the Tracy equation, which containspressure-dependent groups. A differential form of this equation is presented which contains pressure derivatives of the groups, and production and waterinvasion rates, with pressure and time the two main variables. Saturation equations are discussed with regard to the assumptions, particularly that ofrelease of gas in the invaded zone, this being in accordance with the material balance. The use of simple empirical equations for the various quantities issuggested. These must be of a form which give usable values for the pressureand time derivatives where required. Calculated water invasions are comparedfor various theoretical and empirical invasion formulae, with linear andexponential pressure declines. Predictions of a depletion drive by the Muskatand differential Tracy equations are compared, using various empirical relations for the required quantities. Combination performance curves are calculated by the Muskat equation for various ratios of aquifer constant topressure decline constant, both laws assumed exponential. Similar curves are calculated by the differential Tracy equation, with hyperbolic forms for waterinvasion and production rates, taking various sets of values for the constants in these forms. The calculations are programmed for a three-point Runge-Kuttamethod, taking production increments rather than pressure d4eerements where pressure stabilization or in- crease might occur. The use of such methods to optimize a production schedule is suggested.
Effect of Liquid Saturation On Turbulence Factors For Gas-Liquid Systems
Authors: Wong S.W.
Published: March 2010

The effect of a mobile-liquid saturation on turbulence factors for gas-liquid systems was studied by measuring the turbulence factors for a two-phase f10w system using nitrogen-water and limestone cores. The steady-state, two-phase flow tests were conducted at pressure drops of 200 and 400 psi, both at a back pressure of 400 psig.

It was observed that increasing the liquid saturation from 40 to 70 pH cent pore volume could result in as much as an eight-fold increase in turbulence factor. The increase in turbulence factor, together with the decrease in effective gas permeability around the well bore, could result in a substantial reduction in gas-n-ell productivity. It was also determined that the turbulence factors for a two-phase flow system can be approximated by using a turbulence factor – permeability correlation obtained with dry cores, provided that the correlation is established experimentally for the rock type in question.

INTRODUCTION

GAS FLOW IN THE REGION OF THE WELL BORE is generally in the turbulent-flow regime, The pressure drop resulting from turbulent flow is greater than that predicted by the Darcy equation. Forchheimer(1) was first to add an additional term to the Darcy equation to account for this increased pressure drop, and his equation is as follows:

Equation in full paper

For an isothermal system, assuming that the gas viscosity and the compressibility factor are independent of pressure for small pressure changes, a plot of the left-hand side of Equation (2) versus W/Aµ results in a straight line. The slope and intercept of the straight line give the turbulence factor and the reciprocal of the gas permeability, respectively.

The turbulence effect in a gas well is usually determined by well tests; however, the effect can also be evaluated if the turbulence factors βis known. The only published data on turbulence factors are those of Janicek and Katz(2), who correlated the turbulence factors with rock permeability using porosity as a parameter. The applicability of the Janicek-Katz correlation to limestone cores has been evaluated by Gewers and Nichol(3), who found that the measured turbulence factors were an order of magnitude higher than those given by the Janicek-Katz correlation. As shown by Gewers and Nichol, productivity estimates based on the Janicek-Katz correlation would be optimistic by a factor of two. They also measured the gas turbulence factors for the same cores with immobile liquid satu-rations up to 30 per cent pore volume. The results indicated that the gas turbulence factors decreased to a minimum at a liquid saturation of about 10 per cent pore volume and then increased over the saturation range between 10 and 30 per cent pore volume. The present study is an extension of the work by Gewers and Nichol to include measurement of gas turbulence factors at higher liquid saturations and under two-phase flow conditions. Such information would be useful in making performance estimates for gas condensate reservoirs where there is a possible liquid buildup around the well bore.
Comment On "Competitive Environments of the International Oil Industry"
Authors: Watkins G.C.
Published: March 2010

Introduction

A RECENT ISSUE of this Journal contained an article by Z. G. Havlena and J. F. Wasmuth on the international oil industry(1). The article provided a useful and interesting review of the environment in which oil companies operate overseas. This note mainly elaborates and comments on the authors' explanation of trends in world crude oil prices.

Havlena and Wasmuth stated (p. 14) that shortly after the re-opening of the Suez Canal in 1957:

"...famine turned to feast; this created an alarmingly increasing imbalance in the world supply-demand picture. Six main factors caused this disruption :the introduction of import regulations in the U.S.A.;the appearance of very low priced Russian oil in world markets;the discovery of new prolific fields in the countries west of the Suez Canal;indiscriminate and disastrous overdevelopment of the prolific Middle East fields;the spread in the search for and successful discoveries of oil throughout the four corners of the world; andthe relative slowdown of the growth rate of crude oil consumption in the major industrialized nations of the Eastern' Hemisphere, often caused by their unfavourable balance of international payments."

In Section II, the relation between world crude oil prices and costs is examined. Section III discusses Middle East crude oil pricing prior to 1957–58. The reasons for the deterioration in crude oil prices after 1957–58 are assessed in Section IV. The conclusions of the comment are summarized in Section V.

II – CRUDE OIL PRICING AND COSTS

A striking omission from the six reasons listed above is any explicit reference to the relation between the cost structure of the oil industry, especially outside North America, and market price. Actual or potential pressure on existing prices arises if suppliers are willing to provide more oil than the market can absorb at the realized price. Market price would be in equilibrium and not subject to any significant downward or upward pressure if the price were equal to the incremental cost of obtaining additional production from the highest-cost source of supply utilized.

This also assumes that production from lower-cost sources of supply is at desired levels. In economist's terms, this is referred to as the equivalence of price and marginal cost. A price lower than this level of marginal cost would reduce the volume of oil that producers would be willing to sell, and vice versa. Figure 1 illustrates this point. The amounts of oil consumers are willing to buy at various market prices may be depicted by a curve (DD) which will slope downward from left to right, assuming that more oil will be bought at lower prices. The supply curve (SS), which shows output forthcoming at alternative levels of oil prices, will slope upward as higher prices will encourage greater supply. The supply curve may be envisaged by arraying all sources of oil supply in terms of increasing cost.
Continuing Education-What It Takes to Be With It
Authors: Wichert E.
Published: March 2010

With the rapid expansion of knowledge in all fields, the technical man has to guard himself against obsolescence by actively pursuing a program of continuing education. What is involved? In short, time, money and effort on the part of the individual are needed. A brief outline of the available forms of continuing education is given, and these are discussed with regard to time, money and effort.

Whether a person is located in Drayton Valley or Calgary, it is possible to follow a continuing education program to suit each particular location or situation. Theresponsibility for setting and pursuing such a programrests mainly with the individual, but the climate that a company sets is important also.

Introduction

Most Engineering don't argue about the need for continuing education – they admit that continuing education is essential. There is, however, a great gap between admitting to a situation and doing something about it.

Continuing education, as discussed in this paper, is thought of as an educational program that a technical man sets for himself in order to stay abreast of thenew developments within his chosen industry. This goes beyond on-the-job training, as the latter would merely qualify him for a new assignment or position. Continuing education for a young engineer may initially mean a formal one- or two-year company trainingprogram, but it must not stop there. It should be, asthe word implies, a continuously ongoing process of study in one's chosen field of endeavour. This paper points the way to such a program.

Brief Outline Of Sources Of Continuing Education

For reference purposes mainly it is necessary to set down briefly the various sources of continuing education that are available. Not all of these will be readily available to everyone, but, on the other hand, everyone has access to at least two or three of the following:Technical meetings or seminars, usually put on by technical societies, companies or educational institutions.Formal one to three-week courses given by a university school of technology or P .I.T .S.Evening term courses consisting of one or two lectures per week, available at the universities or technical schools.Correspondence courses.Subscriptions to a great variety of technical and trade journals.Books.

What Does It Take To Participate In Continuing Education?

The three obvious and essential things that are required in almost any endeavour are time, money and effort. Of these three, the last, namely effort, is the most important. Effort is the action taken to bring about the desired end result. This applies to any endeavour, as, for example, the team effort to design and build the rockets to land a man on the moon and return him to earth. In this example, the team effort of thousands of people was required to bring about the desired results. Because continuing education is a very individual endeavour, benefiting firstly the individual, it can only be brought about by the individual himself.
Present State of Gas Logging Techniques With the Use of a Continuous Mud Weight Recorder
Authors: Issenmann O. , Lucon C.
Published: March 2010

The addition of a continuous mud weight recorder to the standard gas logging instruments was first recommended three years ago by Societe Nationale des Petroles d'Aquitaine for better control of deep gas well drilling. To this end, a new apparatus, the Densimud, was developed and tested by Geoservices, and has now acquired good reliability and wide use.

New information and knowledge is brought to light by this tool when used in combination with detection and chromatography of gas in mud. These are of prime importance for the accurate localization of gas layers and the prevention of blow-outs.

The Densimud is used either alone or included in a synthetic system, the Geobloc. This comprises a cuttings sampler and washer, the Densimud and the gas trap, operating on a continuous mud stream diverted from the output mud circuit by a special pump. The main fact discovered by this tool is that, even in the absence of gas, a significant decrease of mud weight (up to 0.7 pound/gal.) occurs every time the kelly is unscrewed (for pipe addition for example). When the air introduced in the pipe string by this operation arrives back at the wellhead after a complete cycle, the lag time is accurately recorded at regular intervals. This decrease is not seen by the gas instruments unless the gas-in-mud background is high.

Recorded on the same diagram, the curves for total gas, mud weight and mud pit volumes give a very interesting synthetic picture of what is happening in the well. The successive air peaks are reference marks which make it possible to determine much more accurately than before, the origin of the various gas peaks.

INTRODUCTION

The Value Of A Continuous Mud Weight Recorder over manual measurements is obvious for wells which are liable to give fluid eruptions (gas or water): the control is continuous, accurate and automatic. An alarm may be coupled to the system Furthermore, the mud sampling is more constant and representative.

This method is particularly valuable for gas detection. It has the advantage over conventional gas detectors of a faster response and the possibility of accurately determining the true percentage of gas in mud as soon as this is higher than 1 per cent. The standard gas logging instruments are more sensitive and remain unequalled for small gas shows, but they are not really quantitative because their response depends on the efficiency of the gas trap.

It is also interesting to use two instruments simultaneously one for the weight of the mud injected into the well, the other for the output mud. The difference of weight is often important, depending on the background gas content collected by the mud during its upward travel in the annulus.

THE APPARATUS

The densimud consists essentially of a constant-height column through which mud from the wellhead outlet is circulated by a special pump- at a constant flow rate.
A New Iterative Method For Solving Reservoir Simulation Equations
Authors: Aziz Khalid , Settari Antonin
Published: March 2010

Recently Poussin and Watts have presented some interesting iterative methods of solving matrix equations resulting from the finite-difference approximation of partial differential equations. These methods are however, not competitive with the strongly implicit (SIP) method of Stone for highly anisotropic and heterogeneous reservoirs. Our method is an extension of the method of ‘Watts and it is competitive with SIP from a computational point of view; furthermore our method is easier to program. In this paper, we first formulate the matrix problem using the notation of Stone. Next we present Watts’ method in the notation of our paper. Following this, the new method is developed. Computational algorithms for the implementation of both of these methods are also presented. Finally, we present numerical results and a comparison of several numerical methods.

Introduction

In RESERVOIR SIMULATION and in many other problems involving partial differential equations, we are usually faced with the problem of solving equations of the parabolic type,

(Equation Available In Full Paper)

where n is the direction normal to the bounding surface. In spite of the fact that computers are getting bigger and faster and the cost per computation is being reduced the cost of reservoir simulation in many important cases is still too high and cannot be justified, Efforts are being made to reduce the cost of reservoir simulation. Along with improvements in computers, it is also necessary that more efficient methods be developed for the solution of reservoir simulation equations. This is indeed the case and many new methods are continually appearing in the literature. Many useful techniques are often buried in mathematical details which the engineer usually tries to avoid.

In another paper(1), we have given mathematical details of a new method for solving the matrix equations resulting from the finite-difference approximations of Equations (1) and (2), In addition to the consideration of the boundary condition given by Equation (3), we have also discussed other boundary conditions in that paper. Our objective here is to present important practical results without giving any mathematical details which are not necessary as far as applications of the method are concerned. In order to keep our discussion brief and simple, here we will deal in detail with the solution of the parabolic Equation n) and then show how the same method can be applied to Equation (2). Many important theoretical results not presented here are contained in the companion paper(1), and some of the practical considerations given here are not discussed elsewhere.

Derivation of Matrix Equation

The method to be presented is quite general and can be applied to irregularly shaped domains (like natural petroleum reservoirs); however, to illustrate the method we will choose a;simple example of a rectangular domain as shown in Figure L As usual, we divide the domain of interest into grid blocks and locate a grid point inside each grid block.
Fatigue of Threaded Sucker-Rod Couplings
Authors: Bellow D.G. , Faulkner M.G.
Published: March 2010

Accelerated laboratory tests on the fatigue characteristics of sucker-rod couplings were carried out on a closed-loop hydraulic testing system. The purpose was to evaluate a number of different thread designs currently being used in the manufacture of sucker-rod couplings. The thread forms tested included the simple cut, a keyhole cut and burnished, cut and cold worked and fully cold worked.

The results show that the fatigue life increases as the degree of cold-working increases. It is also seen that the effects of accelerating the testing are insignificant.

Introduction

THE FAILURE OF SUCKER-ROD JOINTS is of considerable interest to those involved in petroleum production. To eliminate or minimize such failures many attempts have been made both in producing new rod and coupling designs and eliminating the coupling altogether. The literature shows a number of papers dealing with the subject of joint failures, specifically related to improving the pin connection. There is apparently very little written on the coupling itself, but there are a multitude of coupling designs commercially available for use in joining sucker-rods. The question arises as to which of these designs is the best. Thus, to aid in the design and selection of a coupling, the purpose of this paper is to evaluate the fatigue life of a number of different thread designs which are being used in the manufacture of sucker-rod couplings.

Coupling design has, for the most part, been consistent with the pin design to which it must mate. Coupling thread design has evolved from the simple cut thread, to a keyhole, burnished, cut and cold worked, and recently to a fully cold worked or rolled thread. Apart from the simple cut thread and keyhole thread, all other thread designs incorporate some degree of cold working in the thread-forming process.

To the consumer the coupling represents but a part of the cost of a rod. However, to the manufacturer, not all coupling designs can be made with the same ease and quality control and, hence, same cost.

The majority of coupling failures are the result of fatigue damage. This damage can be accelerated by improper joint make-up in the field, operating in a hostile environment such as sour wells, manufacturing couplings from materials with poor fatigue characteristics, and the manner in which the thread has been formed inside the coupling. The problems of improper joint make-up have been explored in the paper by Hardy(1). In this same work, reference is made to the influence of corrosion on the fatigue life of sucker-rod materials. Although the scope of the present investigation excludes evaluation of the fatigue life of coupling materials, its main purpose is to evaluate the fatigue life of thread designs found in sucker-rod couplings and compare these results with the fatigue life of the unnotched coupling material.

Testing Program

In any testing program involving fatigue, one of the two major problems to be overcome is to control all but one of the variables involved.
Practical Use of Drill-Stem Tests
Authors: Timmerman E.H. , Van Poollen H.K.
Published: March 2010

Drill-stem testing has advanced from simple sampling of the formation to complete pressure buildup analysis. This paper reviews the mechanical arrangement of the tool, its running and pressure measurements. Various typical drill-stern test pressure charts are shown as an aid in trouble-shooting.

Purpose

THE ORIGINAL PURPOSE of drill-stem tests included recovery of a sample of the formation fluids and possibly measurement of the formation pressure. Today, the nature and use of the drill-stem test is more sophisticated and most techniques developed for drawdown and buildup tests have been adapted to the shorter drill-stem test. These might include computation of formation permeability, k, skin, s, flow efficiency or damage ratio, D.R., productivity index, P.I., and radius of investigation, ri. At times, reservoir discontinuities such as faults, small reservoirs, two-layer performance, lenses in the pay and fluid contacts may be recognized.

A sample of the formation fluids is usually caught at near formation pressure during the test and brought to the surface without release of pressure. If properly removed and transported, such sample might be analysed in a PVT laboratory. At present, the sample usually is only used to establish fluid-type, gas-oil ratio, viscosity, gravity, etc., as measured in the field.

In a drill-stem test the pipe above a shut-off valve is filled with air adjusted by water cushion as the pipe is lowered into the mud-filled well. This valve can be intentionally opened and closed after the pipe has been lowered to the desired depth and packer, set to seal off the mud liquid within the annulus of the well. Thus the well may be produced against a controlled amount of back pressure when the tool is initially opened.

Test Procedure-Mechanical Equipment

Most drill-stem tests taken today are using equipment and procedures developed by major service companies. Some of the tools involved and typical charts for two such companies are included in this paper as exhibits A and H, respectively, to give the reader an appreciation of complexity.

Two or more bottom hole pressure gauges are usually employed. The upper gauge measures the pressure inside the drill pipe or tubing string below the shut-in valve. The lower gauge measures the pressure on the outside of the tool. Both gauges are located near the bottom of the equipment.

A section of slotted pipe is used to permit entry of the fluids from the well bore below the set packers into the inside of the string of pipe. To reduce buildup of pressure ahead of the unset packer while it is being lowered into the well, fluids are permitted to flow through these slots and various other mechanisms located below the shut-in tool. Such fluids constantly move from below the unset packer through the pipe to the annulus above the packer while the tools are run into the well. In most cases this technique results in a shorter running time without damage to the tools or plugging of the slots or other restrictions in the flow string below the shut-in tool in the drill pipe.
Pressure Drop In Wells Producing Oil And Gas
Authors: Aziz Khalid , Govier George W.
Published: March 2010

A simple, mechanistically based scheme for the calculation of the pressuredrop in wells producing oil and gas in the single-phase liquid, bubble and slugflow patterns is described and checked with independent field data. The schemeis based on an identification of the flow pattern through a modification of theflow pattern map of Govier, Radford and Dunn and the application of themechanical energy balance in a form appropriate for the flow pattern assuggested by Govier and Aziz. Predictions for some 48 wells are compared withfield data and with the predictions of Orkiszewski, Duns and Ros, and Hagedornand Brown. The proposed method gives results at least as good as any of theothers, is more soundly based on the mechanism of flow and is independent ofthe data with which it is confirmed.

A computer program for the method and a typical printout are given.

INTRODUCTION

Many methods have been proposed for the estimation of the pressure drop inwells which produce a mixture of oil and gas. These are reviewed in detail by Govier and Aziz. Most of the methods are strictly empirical, but for certain ofthe flow patterns which may be encountered methods based on the mechanism offlow may now be developed. This is especially true for the bubble and the slugflow patterns and, as will be discussed in a following paper, the annular-mistflow pattern encountered with gas-condensate wells.

Orkiszewski has developed a pressure drop prediction scheme based on anidentification of the flow pattern and the application of selected mechanisticand empirical methods to the individual flow patterns. His original appraisalincluded, among others, the Poettmann and Carpenter and related correlations.The most accurate methods, the Duns and Ros and the Hagedorn and Brown werethen tested along with his own scheme against 148 well conditions.Orkiszewski's comparison showed that his method gave improved accuracy overthat of Duns and Ros and Hagedorn and Brown. Espanol et al confirmedthis with data from 44 different wells.