bluuebunny/crossref_metadata_2025 huggingface dataset:
Taber South - Canada's First Polymer Flood
Authors: Lozanski W.R. , Martin I.
Published: March 2010

Three years of actual performance of the Taber South Mannville "B" pool polymer flood has resulted in sufficient data to review the initial decision to implement this type of secondary recovery scheme. Comparison of performance to the original forecasts to a critical re-examination of those forecasts and to the performance of conventional waterfloods in pools with similar characteristics has been made. Operating costs and capital costs caused by polymer injection have been studied. Consideration of ultimate polymer slug size and operational procedures has been undertaken to provide a guide for optimum future performance. The conclusion has been reached that polymer flooding has been economically successful and appears to have been significantly more profitable than a conventional waterflood.

INTRODUCTION

CANADA'S FIRST POLYMER FLOOD was initiated in February 1967 in the Taber South Manriville "B" oil Pool, located approximatehr 35 miles southeast of Lethbridge, Alherta (Figure 1).

The Taber South Mannville "B" pool was discovered in March 1963 with the drilling of the CPOG Taber S 2-29-7-16 well. A total of 23 oil wells and 1l dry holes drilled on a 40-acre spacing- pattern, to an average depth of 3,230 ft, defined a reservoir containing an estimated 40,010,000 st. barrels of oil.

Reservoir Description

ROCK PROPERTIES

The producing horizon is a lenticular Lower Cretaceous Mannville sandstone extending approximately 4 miles in a north-south direction and having a maximum width of slightly more than half a mile, as shown in Figure 2. The reservoir is structurally located on a north-south plunging nose which dips 90 ft from the south to the north end of the pool. The Mannville "B" pool is separated from the adjacent Taber South Mannville "A" pool by a high in the underlying Rierdon unconformity. No gas cap or water zone is associated with this oil pool.

The sandstone is generally homogeneous, with only a few minor shale stringers. The net pay ranges from 6 ft on the west edge to a maximum of 73 ft at the 11-16-7-16 well. The average porosity and permeability for the pool are 26.6 per cent and 2,100 md, respectively. The average water saturation, as determined from restored-state data and later-log calculations, is 9.5 per cent. The average sand properties and reservoir fluid data are shown in Table I.

The cut-offs for determining the net oil pay were 78 microseconds for the sonic travel time and 50 md for the core data) as determined from well completion experience and log data. Less than 1 per cent of the cored sections had a permeability 100ver than 50 md.

Fluid Properties

The fluid properties indicated a highly undersaturated oil reservoir, as the discovery pressure was 1,472 psia and the saturation pressure was indicated to be 415 psia. The latter pressure appears to be low, as bottom-hole pressure surveys indicate the bubble-point pressure to be in the range of 500 psia. The oil contained 65 cu.ft of gas and had a viscosity of 58 centipoises at the saturation pressure.
Development And Utilization of Engineers In an Oil Company
Authors: Mutch J.R.
Published: March 2010

The efficient development and utilization of the individual engineer is one of the most vital tasks facing an oil company. Development of the young engineer starts with the training program and continues throughout his career. The training program seldom really trains an engineer, but it should show him what engineers do, what is expected of them and how they fit into the company.

The first five to ten years of professional experience is the basis of all future technical and managerial growth. It is of extreme importance that the young engineer be exposed to a wide variety of assignments under a number of supervisors in a variety of locations during the initial period.

The rapid development of technology has tended to produce specialized groups within engineering departments. It is essential that these departments be made to interact with other engineering groups and with nontechnical personnel.

INTRODUCTION

OIL COMPANIES are dependent on their engineering departments for most of their plans, programs, studies and reviews. Engineers also contribute many of the creative ideas that make a company grow. In same companies, they handle most of the field supervision. In order to be able to make these important contributions, young engineers need to go through some period of initial training. They must be allowed to develop their full potential and their must also be effective organized.

This paper discusses, what can be reasonably expected from an engineering training program. Engineering development, after the initial training period, is discussed and a program is suggested that will allow the engineer to develop fully. Current organization trends are reviewed and suggestions made that will make the best use of an engineer's special talents and training.

ENGINEERING TRAINING

Twenty years ago, the young man graduating in engineering had a very clear idea of what he wanted the wanted a job! The present-day graduate is quite a bit more discerning the may not have a clear idea of the exact type of engineering work he wants to do, but he has definite ideas on other aspects of his future employment. Most young engineers are looking for a technically stimulating job; they also want to see that they are making a real contribution. Many have ideas that they want to work into supervisory or management jobs at an early date.

What is the best way to utilize this pool of talent that is itching to be put to work? Most of the larger companies have a training program for graduate engineers. Probably the main thing in common is that programs are either being started, changed or discontinued. Most training programs are conceived as a means to train the engineer in the specialized techniques used by petroleum engineers. In practice, this is impossible in any reasonable period of time. At best, the training program acquaints the young engineer with what people do in the engineering department and how the engineering department relates to the company.
Canadian Oil Security And the Impact of Supply Disruptions
Authors: Havlena Z.G. , Holder C.D.
Published: March 2010

This paper examines Canada's role as an industrialized energy-intensive consuming nation in the western world. It focuses on Canada's attitude toward the restricted utilization of its petroleum resources, petroleum being the country's main single source of energy. It examines the political wisdom and the corporate and national economics of Canada's "buy cheap and sell high" oil import/export policy and it attempts to solve, in at least a semi-quantitative way. the "risk/payoff/loss" equation of the international oil poker table at which Canada is but a four- percenter.

In attempting to grapple with this complex subject, the paper first reviews Canada's role as a special member of the Organization for Economic Co-operation and Development (DECO) and the objectives of the OECD which unite the industrial nations of the western world. It then specifically considers:the pattern of energy demand and supply in the OECD community and the international petroleum trade which results from these interrelations;the results of previous supply disruptions in the unstable, but oil-rich, OPEC block which feeds the DEOD nations with oil, and the impact of such disruptions on Canada;the possibility, nature and magnitude of future oil supply disruptions, the resultant scenario, and the impact that they would have on Canada in both physical and economic terms having regard to existing and potential back-up sources of oil supplies.

Finally, the paper attempts to quantify the real cost/ price economics of international integrated producer/ refiners operating in Eastern Canada, for the purpose of determining the profit incentive driving such companies to maintain the status-quo; it also provides the basis of a fundamental benefit/cost study of Canada's oil import policy, without which scrutiny of the "N.O.P." becomes an entirely qualitative exercise (to be presented in Part II).

The paper suggests that the security of Canada's imported oil supplies is diminishing with time due to the current near capacity situation of the aging U.S. and Venezuelan oil industries. It also develops as a basic theme Canada's obligations to the OECD community and the premise of sharing remaining supplies among the energy-hungry DECD countries in times of oil supply disruptions. Because of this concept, the paper notes that a supply disruption amounting to some 20 per cent of OECD demand would be magnified to have double that effect on Eastern Canada.

The paper concludes that Canada is pursuing a policy on oil imports which both jeopardizes the economic security of Eastern Canadians, through exposing them to a growing uninsured oil supply risk and runs against the public interest of Canadians as a whole from a national cost/benefit point of view.

The authors recommend that Canada should take a much closer and more sophisticated look at the changing situation in, view of their preliminary findings. They also suggest that a connection to domestic sources of supply could provide coverage of the security risk noted.
The Effect of Pattern Confinement On Oil Recovery For the Five-Spot Pattern
Authors: Dranchuk P.M. , Jain A.
Published: March 2010

Pilot water floods are commonly conducted in order to evaluate the advisability of embarking on a full-fledged waterflood program. However, it has been known for some time that, as a result of oversweep, recoveries from such pilots tend to be over-optimistic. Consequently, the uncertainty in field recovery predictions based on pilot performance may be quite large.

In order to examine the oversweep phenomenon, a laboratory study was conducted on an isolated five-spot and a partially confined five-spot pattern. It was observed that in the former oil recovery increased steadily until field boundary interference was encountered, whereas in the latter it levelled off at a value of 155 per cent of the oil contained within the pattern. From this it was concluded that confined behaviour cannot be expected of an isolated pattern and that a simple pattern cluster may be used to limit the amount of oversweep.

INTRODUCTION

THE IDEA OF CONDUCTING A PILOT FIELD TEST before proceeding with a fully developed waterflood is almost as old as waterflooding itself. Although the wisdom of conducting pilot floods has seldom been questioned, the ideas concerning the manner in, which the test results should be used have undergone gradual change.

Initially, it was believed that observations made on a pilot represented those which would have been observed had the pilot area been examined during a fully developed flood. The realization that this belief was not generally valid led to a variety of laboratory investigations in order to determine what actually occurred during a pilot flood. During the course of such laboratory studies, it was observed that in a fully developed flood the patterns employed behaved as if they were confined, whereas in a pilot they behaved as if they were unconfined or partially confined. That is, it was observed that in a pilot the movement of the injected fluid is not confined to the area enclosed by the pilot perimeter(1)–(11).

On the basis of these observations and as part of a continuing study in this area, it was decided to examine the effect of various degrees of confinement on oil recovery. Although the authors were familiar with the work of Craig(12) and Bernard and Caudle(l3), they chose to examine the simpler but more cumbersome unconsolidated finite system

EQUIPMENT

The model studied consisted of a 1/4-inch-thick pack of US 30–40 industrial glass beads, confined between two 50-inch-diameter, 2-inch-thick lucite plates which were separated by a lucite washer that measured ¼ inch thick, 50 inches OD and 46 inches I.D. Wells were simulated by means of 1/8-inch-diameter brass tubes which passed through the bead pack and both lucite sheets. Each of these tubes contained four 1/32-inch perforations in the bead pack interval and was fastened in such a manner as to prevent bulging of the lucite sheets when the model was pressured. The model contained a total of 185 wells, drilled on 4-inch centers.
A Reduced Equation of State Applied to Generalized Compressibility Factor Tablest
Authors: Purvis R.A. , Robinson D.B. , Dranchuk P.M.
Published: March 2010

This paper reviews the general problem of finding an equation of state for a pure substance, and discusses the various ways of analyzing the isochores. The approach used was to replace the conventional isometric diagram showing the vapour pressure curve with either a ZT, versus Tr isometric diagram or a P r/Z versus Pr isometric diagram. The latter diagrams show the two-phase envelope which permits use of the saturated state for the origin of individual isochors. This results in the density implicit formulations.

(Equation Available In Full Paper)

which may be conveniently solved with a digital computer.

To demonstrate the method, analytical expressions were developed to represent the compressibility factor tables of Lydersen et a1. For reduced densities greater than one, in the reduced temperature range from 0.3 to 3.0, and the pressure range from saturation to Pr = 30, a standard relative error of 0.65 per cent was obtained with only five constants. The approach is also applicable for reduced densities of less than one, but, at the present time, owing to an inability to 6accurately describe the saturated vapour curve in terms of density, the results are only qualitatively Correct. The sparsity of data for Ze values of 0.25 and 0.29 in this region prevented development of a cross-correlation with Z.

INTRODUCTION

COMPUTER PROGRAMS used for modelling the performance of petroleum reservoirs, or for describing chemical other industrial processes, frequently require a method for calculating fluid densities. This is usually accomplished through the use of a suitable equation of state or through corresponding states correlations, The latter are often used to estimate the density of pure substances, and they can be extended to mixture through the use of the concept of pseudocritical properties.

In order to use corresponding states correlations, a suitable method must be found to adapt the information to computer use. This may be accomplished by applying interpolation techniques to tabular data which have been read into memory, by fitting empirical functions to all or part of the data or by using the reduced form of an equation of state. Of these three possibilities, the use of interpolation techniques is considered to be the least desirable, because large-scale data storage and subsequent retrieval is an inefficient computer operation. The well-known equations of Beattie and Bridgeman(14), and Benedict, Webb and Rubin(15) have been applied in reduced form to generalized correlations by Su and Viswanath(18)

Good accuracy has been achieved using these equations in the gaseous region, but unfortunately it has not been possible to find a single set of coefficients that will give satisfactory results over the entire liquid, gaseous and saturated regions. Hirschfolder, Buehler, McGee and Sutton(7) have developed a generalized equation of state in which different functions are used for the three regions defined as:gas, where the reduced density is less than one;
Drillirng the World's Most Northern Wildcat
Authors: Hood G.L.
Published: March 2010

Planning of the first well to be drilled on Ellesmere Island began in 1969, with the first shipload of expendible drilling supplies arriving on the Fosheim Peninsula in August. Rig selection took place in the spring of 1970 and a helicopter-transportable rig was chosen, due to the rugged mounta.nous terrain on Ellesmere and Axel Heiberg islands. The rig camp, fuel and additional drilling supplies were brought in by ship in August of 1970. The main rig components were assembled in Edmonton and flown to the Fosheim N-27 location in February 1971. The transportation of the fuel and supplies from the beach to the drilling site was carried out primarily by tracked vehicle.

The well was spudded on March 25, 1971, and reached a total depth of. 14.022 feet on December 18, 267 days from spud. Very hard drilling was encountered throughout the entire hole and at total depth 136 bits had been used, including 23 diamond bits. A 13 3/8 -in casing failure forced the setting of 9%-in- casing much shallower than originally programmed and ultimately led to a string of 7-in. casing being set. During the drilling of the well a number of specialized drilling materials, tools and equipment were used.

Introduction

PANARTIC FOSHEIM N-27 was drilled on lands originally formed in from Great Plains Oil & Gas Ltd. et al. The well was drilled by Panarctic Oils Ltd. in partnership with Deminex (Canada) Ltd.

Due to the remoteness of the Ellesmere bland loeation, the high cost of transportation of men, equipment and supplies was the primary consideration in planning the world's most northerly wildcat. As a result of the nature of the Fosheim structure, with 8,000 feet of closure, special precautions were taken against the possibility of encountering abnormally pressured formations. An extra unprogrammed casing string at 12,000 feet made it necessary to drill 6-inch hole for the last 2,000 feel, which greatly reduced the penetration rate and considerably increased well cost.

GEOGRAPHIC LOCATION

Ellesmere is the most northerly of Canada1s Arctic Islands. The drilling site itself is 700 miles from the north pole, 1,400 miles northeast of Yellowknife, more than 2,200 miles from Calgary and 2,600 miles due north of Toronto, as shown on Figure 1. Geographically lhe location, situated atop a 2,000-foot mountain of permanently frozen rock, presented the most difficult access problem of any well yet drilled in the Arctic Islands. In summer months the view from the rig- overlooking the blue open water of Eureka Sound with the 8,000-foot ice-capped peaks of Axel Heiberg Island in the background would rival a spring scene in the Canadian Rockies.

GEOLOGY

The Fosheim anticline is one of the largest known surface structures in the Arctic Islands. The structure lies within the Sverdrup basin, being close to the eastern margin. This large feature is approximately 16 miles long and 8 miles wide covering a total of 25,000 acres.

The Fosheim anticline is a "box" fold, based on the increase of surface dips from the crest to the flanks of the structure.
The Influence of Natural Convection In Gas, Oil And Water Reservoirs
Authors: Aziz K. , Bories S.A. , Combarnous M.A.
Published: March 2010

Natural convection in a fluid layer is a phenomenon which has been the topic of numerous studies. A similar phenomenon has been observed in porous media. In the first part of this paper we review some recent theoretical and experimental studies which allow a better understanding of some quantitative aspects of natural convection in porous media. This review is confined to the case in which compressibility effects are negligible as compared to thermal expansion effects and where the porous layer is homogeneous. Some results are presented on natural convection in a horizontal layer with different types of boundary conditions and in a sloped layer bounded by isothermal planes. Some aspects of mixed convection are also discussed.

The second part of the paper is concerned with practical cases. As a major example we give the description of natural convection occurring in the Lacq gas reservoir. We also present some examples of oil production operations where thermal connection may have an influence. These may be classified into two categories:convective motions already existing in a reservoir and having an influence on the handling of the recovery methods;convective motion induced by the recovery technique itself (thermal methods).

Finally we discuss the case of thermal convection in aquifers, with special reference to the understanding of geothermal areas.

INTRODUCTION

NATURAL (or free) thermal convection in a fluid layer is a physical phenomenon which' has been the topic of numerous studies(l, 6, 11, 28). When in a fluid phase the vertical component of the temperature gradient has the same direction as gravity, the upper layer of the fluid is heavier than the lower and some motions, called convection motions, may exist. These motions tend to reduce the adverse density gradient.

The existence of convective motions in areas of geothermal activity has been known for a long time. The existence of the solid matrix of the porous medium does not modify in any important manner the qualitative aspects of the phenomenon. This analogy between the fluid layer and the porous medium has been justified by a number of recent studies which have also provided considerable quantitative information (7, 12, 19. 22, 24. 26). These studies pertain to the ease in which compressibility effects are negligible as compared to the thermal expansion effect and where the porous layer is homogeneous and bounded by parallel planes.

The problems considered in this paper areconvection in horizontal layers,convection in sloped Jayers andmixed (forced and free) convection.

It is possible to gain a good understanding of the phenomenon for almost all practical cases; however, the direct application of the results to practical problems in a quantitative manner is not always easy. This difficulty is due to the complexity of real boundary conditions, the nonuniformity of a real porous structure and also, in some cases, the influence of compressibility effects.
Enhanced Recovery Trends In Alberta
Authors: Strom N.A. , Bray J.A. , Berndtsson N.G.
Published: March 2010

Application of fluid injection schemes for the purpose of enhancing recovery from oil pools in Alberta has grown from very modest levels in the early 1950s to a current position in which about one-third of the original recoverable conventional oil reserves of the Province are attributed to enhanced recovery schemes. The growth of fluid injection operations bears a rather close relationship to the history of development of the major geological plays in the Province over the twenty-year period. The types of schemes implemented and the recovery improvements generated have been governed by prevalent technology, and other factors such as well spacing practices unitization and levels of market demand. The slackened rate of finding new oil pools combined with the burgeoning demand for crude oil should lead to more attractive price/cost relationships, which in turn should generate new technologic innovations in reservoir displacement and well operating mechanics. Future trends in enhanced recovery operations may be forecast by a consideration of the amounts of oil not recovered by present depletion methods and the risks and potential benefits of emerging enhanced recovery techniques.

Introduction

IS ESTIMATED that by the end of 1972, some 33 billion barrels of crude oil initially in place had been discovered and developed in some 1400 separate pools within the Province of Alberta. These pools cover a combined area of nearly 3000 square miles and are drained by some 14,000 producing wells. Of the total oil in place, about 33 per cent or 11 billion barrels is believed recoverable by the mechanisms currently being applied.

Particularly in the past fifteen years, concerted efforts have been taken to improve the recovery from oil pools in Alberta. As a result, some 3.7 billion barrels of crude oil, or approximately one-third of the total original recoverable reserves, are now directly attributed to the application of enhanced recovery techniques. The more significant of these schemes are distributed across the Province roughly as shown in Figure 1. Today there are about 350 enhanced recovery schemes operating in the Province, containing a total of 2600 injection wells with a combined daily injection of 1.6 million barrels of water, 136 million cubic feet (3) Solvent Floods – horizontal, vertical.

At the end of 1972, the reserves attributed to the major recovery mechanisms being applied in Alberta oil pools were divided in the manner shown in Table 2. Based on these statistics, the following observations can be made:

water flooding- accounts for nearly 90 per cent of the additional oil recoverable by fluid injection schemes; gas flooding has been negligible; vertical flooding is much more efficient than horizontal flooding; vertical solvent flooding, with an over-all recovery factor of 85 per cent, is the most efficient displacement process being applied. Although the over-all gain in recoverable reserves of some 3.7 billion barrels is respectable, the challenge of the next decade here in Alberta may be expressed this way:
A System For Offshore Drilling In the Arctic Islands
Authors: Baudais D.J. , Masterson D.M. , Watts J.S.
Published: March 2010

This paper describes the ‘method used to drill an expendable delineation well from an ice platform 8 miles offshore in the Hecla and Gripe? Bay of the Arctic Ocean. Planning pf the Panarclic Tonn etal CS W Hecla N-52 well began in early 1978. However, a considerable amount of horizontal ice movement data had been collected in 1971 and 1972 in several areas of the Arctic Islands to determine the feasibility of drilling from the ice in the latter months of the’ Winter.(1)

The design and construction of the ice platform, the drilling 1'ig selected for the project, the subsea equipment used and the sequence of operations which were followed to drill the Hecla N-52 well are presented in the paper Flooding of the ice platform began on November 28, 1973 and was completed on February 3, 1974. The Hecla, N-52 well was spudded on March 6 and the rig was released on April 15, 1974. Performance of the ice platform and the special subsea equipment used during the drilling period is reviewed.

Operating experience gathered from the Hecla N-52 well demonstrates that drilling an offshore well in. certain areas of the Arctic Ocean from the ice is feasible.

Introduction

IN ITS OPERATIONS OVER the past five years, Panarctic Oils Ltd. has used heavy aircraft on ocean ice airstrips and moved heavy loads by truck across the ocean ice between islands, recognizing that the thick. ocean ice is capable of being used to advantage in the late winter months. Ice strength calculations indicated that it should be possible to drill offshore wells using the ocean ice as a platform for a conventional landtype rig.

The feasibility of drilling offshore with a slim-hole land rig was demonstrated in the spring of 1973 when a small 150-ton Gardner-Denver 2000 drilling rig was used to drill four stratigraphic tests ranging in depth from 833 to 1700 feet in Kristoffer Bay near Ellef Ringnes Island. The wells were drilled from 1 to 3.5 miles from shore in water depths ranging from 137 to 290 feet. Natural ocean ice, ranging in thickness from 6 to 8 feet, proved to be adequate to support the weight of the rig, for the average 8-day drilling period, with no problems.

Successful completion of the stratigraphic test program, and the results of a load test conducted on natural ice (discussed later in this paper), led to the drilling of the Panaretie Tenn etal CS W Hecla N-52 well in 1974. The expendable delineation well was drilled to a depth of 3080 feet in a known gas field using a conventional rig capable of drilling to 6000 feet, Because the weight of the rig could not be supported by natural ice thickness, an ice platform had to be constructed.

Geographic Location

The Hecla N-52 wellsite is located in the Hecla and Griper Bay, 1800 miles north of Calgary, 950 miles south of the North Pole and 8 miles east of the Sabine Peninsula on Melville Island, N.W.T. as shown in Figures 1 and 2.
Increased Precision of Porosity Measurements Using a Modified Ruska Universal Porometer
Authors: Taylor R.P. , Wardlaw N.C.
Published: March 2010

Porosity can be determined from bulk volumes measured by mercury displacement in a pycnometer and grain volumes obtained by the "Boyle's law" method. The methods are rapid and the sample suffers minimal physical damage and contamination. Using a Ruska universal porometer, precision and accuracy were found to be dependent on limitations imposed by the instrument, the sample and the operator.

The largest errors are in bulk volume measurements, which are affected by the size and shape of samples and by the way in which the samples are oriented in the pycnometer chamber. Significantly large and unpredictable positive volume errors occur in the pycnometers of porometers and porosimeters because of spaces associated with contacts between the sample and the pycnometer walls or cap which are not invaded by mercury.

With the unmodified instrument and procedure, multiple determinations on a standard of accurately known bulk volume gave POSITIVE errors of as much as 0.1 cc and more. This is a 100 per cent porosity error on a sample of 5 cc bulk volume and 2 per cent porosity. More precise measurements are required for many purposes, and the instrument and procedure were modified and the precision on bulk volume measurements improved to better than ±O.Ol cc; with extreme operator care, it is possible to achieve a precision Of ±0.005 cc. The accuracy of grainvolume measurements was found to be ±0.01 cc.

INTRODUCTION

THE PRECISION and accuracy with which pore volumes can be obtained for rock samples using a Ruska universal parameter are governed by limitations imposed by the instrument, the sample and the operator. In this paper, these limitations are evaluated and instrument modifications and operating techniques for optimum precision and accuracy are described.

The porometer consists of a 100-cc volumetric mercury pump with attached pycnometer. Bulk volumes are measured by mercury displacement in the pycnometer and grain volumes by the "Kobe" or "Boyle''s Law" method. Pore volumes are obtained by subtraction.

The main advantages of obtaining bulk volumes in a mercury pycnometer are that the method is rapid and the sample suffers minimal physical damage and contamination. It can subsequently be used, without further treatment, for the determination of other reservoir properties.

Major problems arise for samples with large exterior vugs, as is the case for many carbonate core plugs, because mercury invasion of the exterior vugs results in low values of the bulk volume. However, exterior vugs create problems for all other methods, with the exception of caliper or micrometer measurement.

Sample Preparation

Cylinders of 2 cm diameter and with volumes of approximately 5 to 8 cc were prepared with a Ruska universal core grinder and drill and were subsequently treated with acetone for 2 to 4 hours in Soxhlet''s apparatus, oven-dried at 80=C for twelve hours and then stored in a desiccator. The samples were weighed before and after determinations in the porometer as a check on retained mercury.
Role of Petroleum In a Changing Energy Scene
Authors: Stabback J.G. , Vollman K.W.
Published: March 2010

Prior to the 1920"s, oil and gas were an insignificant part of the Canadian energy supply. During the last fifty years, their use has increased at dramatic rates and today they make up two-thirds of our annual energy consumption. The convenience, low price and plentiful supply of oil and gas undoubtedly have made them the most essential components of our affluent industrial state.

Recent events in this country and offshore, related to the price and security of future petroleum supplies, have prompted an obvious concern among governments, academic communities and the country at large. There is it clear need for a reassessment of our future petroleum supplies and our dependence on that resource. This paper examines that dependence and the future outlook for petroleum availability. To round out the treatment, alternative energy sources are briefly discussed.

INTRODUCTION

"ON THIS CONTINENT, we have less than 15 years of proven oil production in sight; (and) our known re- serves of natural gas, which have been declining in relation to consumption, now amount to less· than 25 years" supply."

Although the words of that quotation have little contemporary shock value, you may be surprised to learn that they were printed nearly twenty years ago in a Royal Commission study on Canadian Energy Prospects, "How little things have changed". is the conclusion one is tempted to make. However, change cannot be gauged so easily. A variety of historical data have been collected for this paper to show the many aspects of petroleum"s changing role in the energy scene. The statistics are interesting, but; more importantly, they provide an understanding of the past, which is a prerequisite for planning the future.

Historical Use of Energy in Canada

Average annual energy consumption in Canada for the past fifty years is shown in Figure 1. The units are trillions of Btu"s per year. A fifty-year study period has been selected for the following reasons:it encompasses the emergence of" petroleum as a major energy source;it includes periods of varying economic growth and the major upheaval of a world war; andreasonably reliable statistics are available for the entire period.

The data shown have been compiled from several sources and it was not always possible to determine the assumptions used by the original authors. As a result, there may be minor discrepancies in some of the values, but the accuracy is high enough to make the trends meaningful. In order to compare hydro and nuclear power with electricity generated from fossil fuels, primary consumption from hydro and nuclear sources has been consumption on the basis of 1 kilowatt hour = 10,000 Btu's.

In the late twenties, coal was our major energy source, supplying about two-thirds of the total primary energy requirements. Petroleum met only 10 per cent.
Compressibility of Natural Gases
Authors: Mattar L. , Brar G.S. , Aziz K.
Published: March 2010

A new correlation for the compressibility of sweet and sour natural gases ispresented. This correlation is derived from an equation of state whichadequately represents the Standing-Katz Z-Factor chart. The algebraicexpression for compressibility presented here is suitable for computercalculations. A FORTRAN subroutine to perform this computation is alsopresented, along with a graphical form of the correlation.

INTRODUCTION

IN THE PRESSURE ANALYSIS of transient or pseudo-steady-state flow Dataacquired during gas well testing, a knowledge of the variation of fluidcompressibility with pressure and temperature is essential. For liquid flow, the compressibility is small and is usually assumed to be constant. For gasflow, the compressibility is neither valid nor necessary of a real gas can becomputed readily.

Trube (1957) has presented graphs from which the compressibility of natural gases may be obtained. This correlation is, however, difficult to usein a computer program. Recent developments have made possible a more consistentand convenient approach.

The purpose of this paper, therefore, is to present An analytical technique forcalculating the compressibility of natural gases. The procedure may be readilycomputerized and was used to generate curves of pseudo-reduced compressibility, which are useful for manual calculations.

Theory

(Equation in full paper)

Graphical Presentation

The computer subroutines mentioned above were used to generate cr as a function of Pr and Tr. Figure 1 is aplot of c r versus pr for various values of Tr. In this figure, the curves are too close together for easy andunambiguous reading. In order to increase the separation of the isotherms, especially for the low-pr range, c r T r wasgenerated and plotted versus Pr for various values of Tr as shown in Figures 2 and 3. The separation between the isothermsin these figures is sufficient to make them easy to read and hence suitable forreasonably accurate manual calculations of compressibility.

Sour Gases

The correlation developed for c r in terms of (aZapr) and the graphical representation of cr Trare applicable to sour as well as sweet natural gases. A simple method has beendeveloped by Wichert and Aziz (1972) to account for the presence of H.S and CO2 in the use of the Standing-Katz Z-Factor chart. Inthis method, the pseudo-critical properties of a sour gas are adjusted togive:

(Equation in full paper)

The calculation procedures are then exactly the same as discussed previously, except that T12 and p1c must beused instead of T2 and po respectively.

Discussion

Figure 4 compares some of the isotherms for reduced compressibilitydeveloped by Trube (1957) with corresponding isotherms from Figure 1 Thedifference between the two methods is no doubt due to the different techniquesutilized to obtain Z and (aZ/a2r)Tr.

Trube used the Standing-Katz Z-Factor chart re- produced by Brown et al.(1948, p.38) to obtain values of Z and (aZ/apr)substituted thesevalues into Equation (4), and calculated c, as a function of pr and Tr.
An Update On Pumping Unit Sizing As Recommended By API-RP-11L
Authors: Griffin F.D.
Published: March 2010

With well over 250 case histories in the form of dynamometer cards taken all over the world in the last decade, it now seems appropriate to review the API recommended method of sizing a pumping unit and compare it with older methods used in the past. The dynamometer cards taken covered a wide range of well conditions and included numerous combinations of gear box sizes and polished rod strokes.

The API recommended practice, API-RP-11L, was first published in March of 1967 and in the more than eight years since its inception has come to be the accepted method of sizing pumping units throughout the industry. However, just how close do the calculations for sizing agreeith measured results?

The gear box torque analysis and the peak and mini-mum polished rod loads taken from each dynamometer card are compared with these same values as computed by the API method as well as the old conventional (Mills) method. Calculations are made for the identical well conditions as shown on each dynamometer card, and deviations between measured and calculated results are plotted and analyzed.

Introduction

The energy crisis now confronting the free world has made the selection and operation of all oilfield production equipment very critical. This is certainly true of oilfield pumping units. Thus, it is imperative that we size a pumping unit to well conditions just as accurately as we know how. It is equally important that we operate the unit within its rating if we are to avoid costly downtime due to breakdowns, This means checking the loading on the equipment periodically and making corrections (if indicated) in counterbalance, polished rod stroke or pumping speed.

It has been more than eight year (March, 1967, to be exact) since the API published its first recommende4 practice for sizing oilfield pumping units. It was designated as API-RP-11L and, in the eight years following its publication, it has come to be an acceptedractice by the industry as a basis for sizing pumping units.

Just how good is the API method of sizing units? What percentage error can we expect? How does it compare with the older conventional (Mills) method f sizing units ?

In an attempt to answer these and other questions concerning sucker rod pumping, 250 dynamometer cards accumulated by Lufkin over the last thirteen years were examined. Dynamometer cards are, of course, nothing more than a continuous plot of polished rod versus polished rod displacement for one stroke of the pumping cycle. The 250 dynamometer cards were taken on wells covering a wide range of conditions and in locations all over the world. Dynamometer cards which revealed obvious well abnormalities were thrown out, All others were included, Of the 250 wells examined, 124 were equipped with conventional crank-balanced nits, 109 were equipped with Mark II units and 17 were equipped with air balanced units. (A tabulation of the measured conditions and calculated predictions for each of these 250 cases is included at the end of this paper.)
Behaviour of Crude Oil Under Fresh-Water Ice
Authors: Chen E.C. , Keevil B.E. , Ramseier R.O.
Published: March 2010

Experiments were carried out in a cold room at −15 °C to investigate the behaviour of Norman Wells crude oil under fresh water ice. The crude, when injected in water under the ice, separates into droplets and rises to the ice-water interface, where the oil droplets coalesce to form a slick. The spreading of oil under ice is complicated by the coalescence of oil drops at the ice-water interface, and the spreading process is found to be different from that of oil on water or on ice. If sufficient turbulence exists in the water, both oil-in-water and water-in-oil emulsions are formed. An oil lens sandwiched between the ice acts as an insulating layer and thus increases the temperatures drop cross the ice.

Introduction

The discovery of oil in commercial quantities in Northern Canada could lead to the construction of oil pipelines to the southern markets. Such pipelines would cross many rivers and streams that are subjected to ice conditions of varying seasonal length. It is conceivable that oil spills under ice-covered rivers may result from such pipeline crossings, The spills can be large, such as those caused by a major pipeline fracture, or they can be small, such as those developing through holes of a few centimeters diameter in the pipe. In addition, accidents involving oil tankers, storage tanks and tank trucks may also result in oil spills in ice-covered rivers.

Although results on oil pollution research are published in an increasing number, available information on the behaviour of oil spilled under ice is limited. The only systematic study reported in the literature is by Wolf and Hoult(1). They investigated the effects of crude and diesel oils on the porous substructure of Arctic sea ice and found that the oil, when injected under the ice, was pocketed below the ice surface. They also reported that as freezing continued, more ice formed beneath the oil and that the oil acted as an insulating layer impeding the flow of heat- However, in order to assess the effect of an oil spill under ice-covered rivers and to help in developing clean-up techniques for such an oil spill, more must be understood about the behaviour of oil under ice, The present work investigates the behaviour of crude oil under fresh-water ice, Parts of the work were presented at the 1975 Conference on Prevention and Control of Oil Pollution(2).

Experimental

A circular aluminum basin, 150 cm in diameter and 70 cm deep was installed in a cold room where the temperature was maintained at −15 ±2 °C. Heating tapes were glued to the outside of the tank and covered with 10 cm of polystyrene insulation. The heating tapes were connected to variacs set at very low power to cancel out the bottom and side heat losses. This arrangement resulted in one-dimensional freezing in the basin, A stirrer was mounted on the side of the basin and a circular boom installed to prevent the oil from rising up the tank walls.
A Provincial Resource Development Research Policy
Authors: Flock Donald L.
Published: March 2010

Introduction

On december 6, 1973, the Prime Minister of Canada, during a debate on the energy crisis, said: "We must consider the national action and the national commitment that will be required in achieving the capacity for (energy) self sufficiency which is our objective." Whatever self sufficiency the Prime Minister is referring to, it can be attained only at high cost, high risk and with a concerted effort on the part of all the people of Canada. What is the provincial commitment to assist in reaching this goal? In order to develop self sufficiency in energy we must first have the natural resources. Secondly, we must have the technological capability and the knowledge to manage and develop these resources.Thirdly, we must have the physical ability, manpower and time to install such production facilities as may be necessary to make self sufficiency in energy a fact of life. Finally, it must be clearly recognized that there is an adequate monetary incentive and suitable availability of the capital required to accomplish this major task. Although there are many sources of nergy in Canada(1), from a provincial point of view those with which we are most concerned are oil natural gas and coal. In Alberta, we are blessed with an abundance of these three resources, however, only a very small portion of the Alberta oil sands and coal resources are commercially accessible to surface mining techniques. It is quite apparent that some in-situ technological breakthrough will be required, which will mean a concerted research effort at the provincial level. It is the purpose of this paper to present certain concepts and recommendations for a coordinated provincial resource development research policy for the Province of Alberta. It should be mentioned that "research", as utilized in thispaper, covers basic and applied research and development.

Petroleum

In an address to the 10th Commonwealth Mining and Metallurgical Congress in Ottawa on September 3. 1974, dealing with the "Energy for Tomorrow and Beyond", A. E. Pallister(2) relates the potential domestic demand for future oil to the domestic supply. Sources of supply are from (1) present reserves, including- enhanced recovery, (2) new discoveries in the Western Provinces, (3) oil sands (by mining), (4) oil ands (in situ), (5) Atlantic and Eastern off-shore, and(6) The Western Arctic and the Eastern Arctic. It may be noted that his estimate assumes that by the year 1985, part of this domestic demand will be met by an approximate 350,000 barrels per day of production from mining operations in oil sands and roughly150,000 barrels per day of production by in-situ recovery operations. To obtain 350,000 barrels per day by mining requires the equivalent of almost two Syncrudes and the existing Great Canadian Oil Sands operation. e have yet to have a full-scale project which would even beginto meet a part of the 150,000 barrels per day ascribed to in-situ techniques. One must question whether or not such quantities of oil from the tar sands of Alberta can be obtained by 1985.