bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Developments in Gas-lift Methods in California Oil Fields
Authors: Bell A.H.
Published: June 2014

The general principles of the gas-lift will not be described in this paper.Only specific details that have not been fully discussed in previous papers, orresults that do not fully coincide with conditions previously described, willbe dealt with. The principal points to be emphasized and for which supportingdata are furnished are as follows:Gas-lift installations usually have comparatively high efficiencies ascompared with standard pumping equipment, when reduced to a basis of barrelsproduced per horsepower installed.Advantages of high-pressure plants from the standpoint of operatingefficiency and for the application of the gas-lift early in the life of flowingwells.Evidence of increased ultimate yield through conservation of gas by thegas-lift.Possibility of development of new equipment to increase efficiency of thegas-lift.Indications of the advantages of repressuring as a means of stabilizinggas-lift wells and as a means of increasing ultimate yields.

Types of Installation

The gas-lift installations of the more important companies in Californiahave been of the central-plant type wherever field conditions would permit.This has resulted in greater flexibility and lower installation costs per wellthan could be obtained with individual well units. In general discussions ofthe gas-lift method of production, the installation costs are frequentlyreferred to as being too high for economical operation. If the field conditionsare carefully analyzed and the plant designed with the idea of obtaining highoperating efficiencies, the installation cost per well can be loweredsufficiently to compare favorably with individual well-pumping units, when theoperating advantages are considered. Much greater production per horsepower canbe obtained with the gas-lift than is possible with pumping equipment.
The "Gas Factor" as a Measure of Oil-production Efficiency
Authors: Uren Lester C.
Published: June 2014

Field studies and laboratory research have established the fact that, theexpulsive force which drives petroleum into wells, from the reservoir sands inwhich it is stored by nature, is primarily an expression of the energy latentwithin compressed natural gas dissolved or occluded in, or otherwise associatedwith the oil. Each barrel of oil produced is forced into the recovery well bythe expansive energy of a certain volume of compressed gas, originally storedwith the oil in the pores of the reservoir rock; and each cubic foot of gas soproduced with the oil and expanded to atmospheric pressure reduces by so muchthe total natural energy available for oil expulsion. This relationship betweenthe volumes of gas and oil produced has seemed so important that petroleumproduction technologists have come to regard the "gas-oil ratio," orthe "gas factor" as it has been more conveniently termed, as a measureof oil-production efficiency. Different methods of oil recovery and productiondevices are now compared on this basis and estimates of ultimate recoveryobtainable through their use are considered by many to be inverselyproportional to the values of their respective gas factors.

The writer has been among those who have given support to a widespreadmovement toward a proper recognition of the significance of the gas factor as aguide in the control of producing oil wells, and does not wish to oppose itsmore extended application. It seems necessary, however, in view of the almostelemental faith with which the principle of the gas factor has been received inmany quarters, to point out that it is a most complex factor, and one whichcannot be regarded as an absolute index of production efficiency without dueregard to other contributing factors by which it is influenced to an importantdegree.
Handling Congealing Oils and Paraffin in Salt Creek Field, Wyoming
Authors: Wood F.E. , Young H.W. , Buell A.W.
Published: June 2014

This paper summarizes the results of laboratory tests conducted to determinethe properties of the paraffin or rod-wax encountered in the Salt Creek field, Wyoming. It also describes field tests and methods employed to cope with theparaffin problem. The conclusions to be drawn from the laboratory work are:Samples of Salt Creek paraffin range in consistency from soft to hard, the melting points varying from 120? to 156?F.Masses of soft paraffin are soluble to an appreciable extent in crude oiland its liquid fractions at temperatures somewhat below the melting point ofthe paraffin. Hard paraffin is very slightly soluble under theseconditions.Agitation apparently increases the amount of paraffin that will go into solution.Paraffin congeals from solutions upon cooling to the point of saturation, which is in all cases below the melting point of the paraffin.Crude oil is the most effective of all the solvents for holdingparaffin sin solution.Pressure alone does not appreciably affect the solubility of paraffin incrude oil nor does it aid materially in holding paraffin in solution when thetemperature is reduced.Natural gas in solution under pressure does not appreciably increase thesolubility of paraffin in crude oil, but is effective in holding paraffin insolution when the temperature is reduced.A foreign body introduced into a solution of paraffin in oil is immediatelycoated with paraffin if the temperature of the solution is at or below themelting point of the paraffin, and the object is considerably cooler than thesolution.

It may not be entirely correct to say that paraffin is taken into solution;it is impossible that the paraffin may be in suspension rather than insolution.
Pumping Deep Wells in the Seminole Field, Oklahoma
Authors: Kirwan M.J. , Covell K.A.
Published: June 2014

This paper covers a brief discussion of pumping 380 to 410 gravity oil fromWilcox sand wells ranging in depths from 4000 to 4900 ft. in the Seminolefield, Oklahoma.

As recently as a year ago it was the general belief among Seminole operatorsthat most wells in that district could not be successfully or economicallypumped. Also the idea was prevalent at that time that the crookedness of therotary holes would cause a large amount of mechanical trouble and the use ofthe air-gas lift would leave the wells depleted with sand conditions and fluidlevels unfavorable for pumping. At that time it was predicted that wells wouldbe abandoned when the economic flowing and swabbing period was reached.Contrary to these beliefs it has been demonstrated that wells can be profitablypumped to limits as low as 10 bbl. of oil per day where conditions arefavorable.

The Seminole field, unusual in its rapid development, has served as anexperimental laboratory for many oil field pumping devices with which thispaper will not concern itself. Discussion will be confined to equipment andmethods in general use throughout the field. The outstanding features ofequipment and pumping operations covered in this paper may be summarized as follows:Pumping equipment from the standpoint of prime movers, energy cost, powertransmission equipment, derricks, counterbalances, beam hangers, tubing, suckerrods, pumps, etc.Pumping problems peculiar to the Seminole field, including the proper timeat which to change from air-gas lift flowing to pumping.

Pumping Equipment

There have been no basic changes in pumping equipment in the past 20 yearswith the exception of some refinements in design brought about by the demandfor equipment suitable for pumping deep wells.
Analytical Principles of the Spacing of Oil and Gas Wells
Authors: Phelps Robert W.
Published: June 2014

It is gratifying to observe the growing interest in the study of oil-wellspacing. It should always be held in mind that the problem of optimum spacingis to obtain the maximum return of capital per acre drained. This naturallyevolves into a mathematical consideration. As mathematics is the basis of allscience, an effort should be made to develop formulas which involve dataobtainable in the early stages of development.

The first information from a discovery well in a new field would be thecharacter of the sand, rate of initial production of oil and gas, viscosity ofthe oil, rock pressure, etc. Later, from this well, if Herold's theories ofhydraulic, volumetric and capillary controls are accepted, could be determinedthe ultimate production as without interference from drainage by subsequentwell completions, and under which control the well is producing. If it shouldprove to be producing under capillary control, a rough estimate could be madeof its radius of drainage. With but one well, the radius of drainage, or theinterference of drainage of individual wells by close spacing, would beestimated by comparison with similar conditions in other fields in which thedevelopment has progressed sufficiently to furnish the data. A second well thatis spaced sufficiently close so that an interference can be observed after itsultimate production is estimated, will furnish data to develop a desirablespacing of wells which can be inaugurated for that area and which is capable ofproducing a uniform amount of oil under like conditions. In some fields thisarea will be extensive, in others each well location will require an individualstudy.

In 1924, Cutler developed a scheme whereby he determined by tabulation aspacing of oil wells for the maximum return per acre.
Relative Propulsive Efficiencies of Air and Natural Gas in Pressure Drive Operations
Authors: Power Harry H.
Published: June 2014

The relative merits of air and natural gas as propulsive agents in pressuredrive operations have been discussed for a number of years. When air or gas isintroduced into the sand, various factors lead the operator to the selection ofwhat he believes to be the proper propelling medium; but when the question of relative drive effect israised, several physical and chemical premises must be taken into considerationin arriving at a conclusion as to the superiority of one medium over the other.Dow and Calkins and Beecher and Parkhurst have contributed fundamentalexperimental work on the effect of dissolved gas in lowering the viscosity andsurface tension of crude oil. Herold and Tickell have indicated that whatevertype of reservoir control obtains, gas plays other important parts in the movement of oil towards the well, namely:The propulsive and expansive force of the gas.The "Jamin effect," or resistance to the movement of oil in a porousmedia due to the formation of gas bubbles.

When quantitative studies are made, parallel conditions must be selectedwhereby we may say definitely whether air is superior to gas as a drivingmedium, or vice versa. Examples of similar conditions are not easy to find inthe field. However, in the laboratory we can make determinations which may leadto general conclusions when applied to the field. The experimental and researchwork described here was started at the laboratories of the University ofCalifornia in January, 1927, and completed in private laboratories at Tulsa, Okla., in February, 1928. The apparatus used was designed especially for thework.
Natural-flow and Gas-lift Experiments and Apparatus
Authors: Brandenthaler H.H. , Wade G. , Morris W.S.
Published: June 2014

Petroleum engineers generally are of the opinion that the flow conditionand, therefore, the formulas that apply to the flow of oil and gas in long pipelines differ in many ways from flow conditions in oil wells. One of the reasonswhy the formulas in common use for pipe-line flow do not correctly apply to oilwells is that t he flow lines arc vertical and not horizontal. Another factorto be considered is that the fluid is a mixture of oil and gas and that thephysical characteristics of these two components are affected differently bychanging conditions of pressure and temperature during upward flow.

Realizing the need for accurate data on flow in vertical pipes under conditionscaused both by natural flow and the gas-lift, the U. S. Bureau of Mines hasinstalled equipment at the Petroleum Experiment Station, Bartlesville, Okla., for the purpose of studying this problem. In addition a study will be made ofthe comparative effects of different natural-flow and gas-lift methods ofproducing oil on ultimate production from reservoir sands.

Experimental Equipment

The experimental equipment consists of a regular oil-field steel derrick, alarge pressure tank installed in a concrete pit beneath the derrick floor, compressors and pumps, gas separators and absorbers, metering and controldevices, and the necessary pipe connections. The crown-block level representsthe derrick floor at an oil well, and the "producing sand? is the pressuretank below the derrick floor. The difference in elevation between thecrown-block level and the tank is 90 ft. Figs. 1, 2 and 3 show the constructionand exterior arrangement of the equipment.

The success of the experiment will of course depend largely upon the accuracyof the oil and gas measurements and the temperature and pressuredeterminations.
Study of Unitization in the Rocky Mountain Region
Authors: Wood F.E.
Published: June 2014

Since the earliest discoveries of oil in the Rocky Mountain area the spiritof cooperation in drilling and production programs has prevailed. There hasscarcely been a field which has not been developed in an orderly manner throughmutual agreement between competitive operators. An appreciable saving hasresulted, as many unnecessary wells have been eliminated. We have unitoperation plans and agreements which were developed at an early date. RockRiver, found in 1918, has been a unit operation. One of the first prorateagreements ever attempted was made in Salt Creek in 1921. Teapot, firstdeveloped in 1922, has been a unit operation; the lessee, the Government, andthe lessor, one operator. South Casper Creek, found in 1918, has been developedas a unit. Rex Lake, found in 1923, is a unit operation. The list might beextended materially but it serves to indicate that the Rocky Mountain regionenjoyed the fruits of unit operation at an early date.

It is concluded from this unitization study in the Rocky Mountain region thatthere is an appreciable saving in both development and production costs as wellas the elimination of waste of a natural resource. Certainly, when unitoperation conserves an irreplaceable natural resource as well as capital, anylegal or political impediment to its successful development will beovercome.

If one company supervises the operations in one field, it appears to be a unitoperation. This may not be true if the lands involved have been leased from agreat number of lessors. Royalty holders create a most intense competitiveoperation. The Rocky Mountain region has its full quota of such diversifiedinterests.

The original study calls for consideration of two types of fields, unit andnear-unit operation. This Committee has felt that if an agreement of anycharacter has brought about a saving it is an approach to unit operation. Thefields have been classified into four types:Unit Operation.-Any field whereby the competitive drilling-drainage featureis or will be absent in the development and operation of the pool.
Unit Operation in the Rock River Field, Wyoming
Authors: Emery Wilson B.
Published: June 2014

The discovery well in the Rock River field, in Carbon County, Wyoming, camein May 1, 1918. The field is on a large anticline having more than 1500 ft. ofclosure and production is obtained from three sands of the Dakota group. At itspeak, production approximated 10,000 bbl. daily and is now averaging 2200 bbl.Total production to Jan. 1, 1930, exceeded 12,500,000 barrels.

So far as known to the writer, Rock River was the first light oil field in theRocky Mountain region to be produced under what we now term unit operation.Though this type of operation was not popularly acclaimed by the oil industry, the Federal Government and the public until many years after the inception ofdevelopment at Rock River, the officials of the Ohio Oil Co. when acquiringthis property were fully cognizant of the economies to be effected by unitownership and the consequent elimination of competitive drilling and producingof wells, and had this in mind at the time. Thus unit management was introducedin this field at an early date by this company.

Area and Management

Fig. 1 shows the location of all wells drilled on the Rock River structure andthe outline of the productive area as now defined, which amounts to 1380 acres.The hachured line indicates the area now under unit ownership; originally amuch larger area was so owned but leases have been canceled as progressivedevelopment indicated their lack of oil.

The management and operation of the entire productive area is handled by theOhio Oil Co., which owns the majority working interest. The Continental Oil Co.with a 20 to 35 per cent. interest in much of this acreage, and smallerinterests owned by others in some of the leases, constitute the remainder ofthe ownership.
Unit Operation as Proposed for the Hiawatha, South Baxter Basin and North Baxter Basin Gas Fields in Southwest Wyoming and Northwest Colorado
Authors: Nightingale William T.
Published: June 2014

The three gas-producing "pools" discussed in this paper are inSweetwater County, southwest Wyoming, and Moffat County, northwest Colorado.Hiawatha,.North Baxter Basin and South Baxter Basin gas fields becameeconomically important in 1929 when a 330-mile gas line connected them withSalt Lake City, Ogden and towns en route. This development immediately focussedattention on the gas-producing fields and the efforts of the producing companyto develop them in an orderly, economical manner. Several outstanding interestswere acquired and working agreements made with others.
Unit Operation in Hidden Dome Gas Field, Wyoming
Authors: Emery Wilson B.
Published: June 2014

The Hidden Dome gas field, situated in Washakie County, Wyoming, wasdiscovered Sept. 26, 1917. Subsequently five additional gas wells werecompleted and a large reserve was developed. For a number of years this fieldcompletely supplied the domestic market at Basin and Greybull, as well as therefinery at the latter town, and it is still supplying gas in small amounts tothis market.

Production is obtained from the sands of the Frontier formation at depthsranging from 1000 to 1500 ft. The original rock pressure was 725 lb. andinitial production ranged from 4,000,000 to 28,000,000 cu. ft. per day perwell. Porosity of the sand, determined from the size of the productive area andthe amount of gas recovered, is over 18 per cent.

Area and Management

It is estimated that the productive area is about 640 acres. Its outline isindicated on Fig. 5, on which are also shown the locations of holes drilled onthe structure and the area of unit operation.

The unit area is owned by the Ohio Oil Co. and development and operation havebeen by this company. No productive well has been completed outside this area-.The entire area was Government land filed on under the placer mining law.

Results of Unit Operation

With six producing wells, or an average of one to each 160 acres, the pool iscompletely developed. Location of the wells was made with respect to structuralconditions plus the requirement that at least one well be drilled on each160-acre placer claim. Perhaps a somewhat more uniform spacing of the wellsmight have been accomplished and one well eliminated, but it must be borne inmind that the holes, on account of their shallow depth, were not expensive andthat the object was to develop as reliable a reserve as possible. There is nocause to suspect that these holes' have not adequately drained the reservoirand there is every reason to think that any additional wells, which might havebeen drilled under diversified ownership and operation, would have been aneconomic waste.
Unit Operation in California
Authors: Jensen Joseph
Published: June 2014

No outstanding example of an important producing unit operation exists in California today where the competitive drilling drainage feature is or wasentirely eliminated We need not feel, however, that the thought of unitoperation had its birth in 1924, when Henry L. Doherty named and sponsored itso strongly before the American Petroleum Institute and our own organization.No man or company in California ever drilled a wildcat well without exertingevery possible effort to get all of the structure, so as to control drillingand avoid competition. Overproduction did not begin in 1923, so there hasalways been the wish to avoid it. In this state the practice of selling acreagearound a wildcat has not been followed, except possibly in rare instances. Theoperator drilling the wildcat knew he must pay the bill alone, so he endeavoredto get the benefit of his effort by tying up all of the land around his welland by so planning his different lease obligations as to avoid as muchoffsetting as possible. If he failed to get all of the land, it was becausesomeone's price was too high, some other oil man also had the same idea andalready held some lands, a competitor took leases away from him while his workwas still incomplete, or (as was so often the case) the hidden structure whendeveloped did not prove to be where the wildcatter thought it would be. Thelast named condition often led to a forced drilling campaign by the last leasessecured and thus to serious drilling drainage problems.

Ownership of the Land

The land situation differs a great deal in various parts of the state. In theSan Joaquin Valley, all the land is surveyed into sections and townships.Railroad land grants embraced a part of the land. In the areas that weredeveloped at an early date, as at Kern River, Coalinga, McKittrick and theSunset-Midway field, such land as the railroad company's diligent landdepartment had been unable to sell for a song as grazing land still remained inits ownership.
Suggested Procedure for Exploitation of an Oil-bearing Structure by Unit Operation
Authors: Corbett C.S.
Published: June 2014

There is much comment at present in the ranks of the oil industry regardingunit operation of oil fields and the benefit that would accrue if it could beextensively applied. It seems certain that, as an immediate corrective of thepresent situation, overproduction could be effectively curtailed with all theadvantages of proper conservation of petroleum resources and with no importantloss to anyone connected with the industry.

Unit Operation in Certain Foreign Fields

Many an oil operator in America would doubtless like to have exclusive controlof one or more oil-bearing structures for development in accordance with theeconomic position of the industry and especially in accordance with the bestproduction practice known. A few operators now have this privilege, particularly in certain foreign fields, and are following lines of procedurewhich show that they are aware of the great opportunity that is theirs. We findin an article by Professor Strigeoff, and in a paper read by Captain Cominsbefore the American Petroleum Institute, the outlines of procedure adopted, respectively, by the Soviet Government for the nationalized Russian oil fieldsand by the Anglo-Persian Oil Co. for its fields in Persia.

Comprehensive plans for the unit operation of other oil fields may have beendescribed publicly but no such descriptions have come to the attention of thewriter. New fields are coming more and more into the hands of single operatorsor of a few who control large activities and who appreciate fully the need forcooperative action and are willing to forego the lure of a large quick profitfrom high flush production in order to secure the advantage of betterstabilization in the industry and a larger though more deferred profit byoperating the field as a unit.
Production Engineering in 1929
Authors: Millikan C.V.
Published: June 2014

Production engineering has continued its rapid progress during the pastyear. Many engineering efficiencies long practiced in other industries arebeing rapidly accepted by the oil industry and every branch of development andproduction work is undergoing study that is reducing the time and hazard in thedrilling of wells even for greater depths, is securing better service fromequipment, and is obtaining greater ultimate recovery from thereservoirs.

Deviation of Drill Holes

Deviation of drill holes probably has attracted greater and wider study thanany other subject. Until about one year ago it had been given little attention.Some California operators knew the common magnitude of deviation, butMid-Continent operators hesitated to believe that holes could be drilled socrooked. The great emphasis and publicity given to the seriousness of theproblem resulted in the design of many instruments to record the deviation bychart or photograph. Instruments which would give the direction as well asdeviation were not generally favored because of the grave fears of the legalcomplications which might result if the bottom of a producing well should proveto be on a neighboring lease. With all the instruments available fordetermining deviation, the use of etching on a glass bottle by hydrofluoricacid is still the most common method employed.

The beneficial result of this earnest effort to drill straighter holes isproved by a comparison of deviation of wells completed recently with thosecompleted over a year ago. The time of this change is arbitrarily taken as Jan.1, 1929, as at that time the operators were aware of the deviation whichusually occurred, and most of them were making some effort to reduce it. Table1 shows averages of wells completed by several companies.
A Theory of Well Spacing
Authors: Haseman W.P.
Published: June 2014

The well method of producing oil and gas is universally used in thedevelopment and operation of oil and gas properties. It consists essentially inthe spacing of a number of wells on a given tract, and in drilling andoperating them in accordance with established practices. The method is based ona fundamental energy principle. This principle governs the state and the changeof state of fluids or fluid mixtures confined under pressure within a porousand permeable reservoir in such a way as to direct a flow from the reservoirinto and out of a drilled well with a reduction of potential energy.

The application of the well method of producing oil has given data which provethat the total yield of oil from a reservoir through wells is, in general, onlya small fractional part of the total oil that is contained in the reservoir. Itis generally recognized that a spacing of one well to each 160-acre tract ofany good oil pool is too wide. However, one well to this 160-acre tract willyield a large quantity of oil and in time will dissipate most, if not all, ofthe potential energy that was originally stored and retained in the fluids bypressure. Two wells spaced and drilled on this 160-acre tract would yieldapproximately twice the quantity of oil, while four wells would yieldapproximately four times the oil.

A well spacing is soon reached, with the addition of wells to this 160-acretract, in which the drainage interference of offset wells will materiallyaffect the yield of oil per well. The increased yield of oil, therefore, is notdirectly proportional to the added number of wells but the increased costs ofdevelopment are directly proportional to the added number of wells. It isevident that while an added number of wells to this 160-acre tract yields anincreased quantity of oil, there is an economic limit to the number of wells tobe added.
Spacing of Wells in the Long Beach Field
Authors: Roberts Dwight C. , Sweeney Stender
Published: June 2014

The spacing of wells in Long Beach oil field has caused much discussion fromthe earliest days of its development, on account of the closely drilledtown-lot areas which have been as intensively developed as any productive areasin the world. The purpose of this paper is to present the results obtained fromthis type of development in comparison with the more widely spaced developmentin this field, now that a sufficient length of productive life has elapsed. Theintensity of development in Long Beach is indicated by the fact that up toSept. 1, 1929, there were 1736 wells either drilled or drilling. Of these 165 failed to get production and 121 were drilling. Thus 1450 wells have producedoil from an area of 1350 acres. Up to July 1, 1929, these wells produced atotal of 355,047,913 barrels.

Method Pursued

Four groups of offset areas were chosen, in each group the wells in one areaare widely spaced and in the other, closely spaced. The areas in each group arecontiguous and the groups are spread over the field from the southeast end tothe northwest, so that representative data are assured. The comparison has alsobeen extended to shallow and deep zones, like zones in their respective areasbeing compared.

Even though these productive zones are very thick, a fair picture of results isobtained, because the drilling of the wells in the two types of areas wasconcurrent in the different groups and, as a rule, the thickness of sand openedup at anyone time was about the same. As deeper sands were found, wells inoffset areas were deepened or new ones were drilled in both types of areas. Thedivision of zones was made in the same manner in contiguous areas.

The total cumulative production up to July 1, 1929, of the wells in theirrespective zones in each area was obtained. From these figures were computedthe recovery per well, recovery per acre, acreage per well, and the ratios ofthese factors. Thus July 1, 1929, is the end of the period considered in allareas.
Quantitative Effect of Gas-oil Ratios on Decline of Average Rock Pressure
Authors: Coleman Stewart , Wilde H.D. , Moore Thomas W.
Published: June 2014

It is recognized that in the early days of the petroleum industry oil wasproduced with practically no scientific or fundamental knowledge of the lawsand principles governing its extraction from the ground. Only a few, if any, ofthose exploiting the oil resources made any effort to collect accuratescientific information. There was little need for it, for as is frequently thecase where the supply of a natural resource appears inexhaustible and isgreater than the demand, large profits were possible from merely skimming thesurface with little regard to the efficiency or thoroughness with which the oilwas obtained. With this policy in force, great quantities of gas were wastedand when the reservoirs ceased producing by natural means they still containeda large fraction of the oil originally in them.

The present tendency in the industry is toward conserving existing oilreserves. In order that greater percentages of the oil present in the groundmay be recovered, efforts are being made to improve production methods and torework depleted fields. If the production methods are to be improvedintelligently it is essential that the fundamental laws be known andunderstood, consequently large amounts of money and effort are being spent ingathering data that will serve to define and interpret these laws.

A great deal of attention is being focussed on the study of the motion of oilthrough an oil-bearing sand, the forces that cause it to move and the factorsthat affect its motion. It is recognized that one of the important factors ispressure, but its quantitative effect is not known. In a given field the rateof production declines with time and so does the rock pressure.
Condensation Effect in Determining Gas-oil Ratio
Authors: Morris Alexander B.
Published: June 2014

In a recent paper on the intermittent injection of gas in gas-liftoperations as opposed to continuous injection, Morgan Walker presented acomparative table showing the effect on oil and gas production from the samewells under the two methods of operation. This table carried a column showingthe formational gas…oil ratios under each method, computed by deducting thevolume of input gas from the volume of trap gas.

During the entire spring and summer of 1928, the present writer had beenengaged on some extensive test car tests of rich gas in Glenpool, seeking, primarily, for an explanation of the apparent loss of gasoline during thesummer season between the field meters and the plant master meter. Tests atseveral of the field meters where the richest gas was obtained regularly failedto check with other tests on the same gas made farther along the line, and thedifference was not made up by the quantity of drip gasoline collected betweenthe points. In the course of these tests, the final outcome of which isimmaterial to the present purpose, an attempt was made to construct a curverepresenting the relationship between gasoline content of the gas in gallonsper thousand cubic feet and the shrinkage in the volume of gas treated as aresult of removing the condensible fractions. Such a curve was made, expressedin units of gallons per thousand cubic feet on the abcissa and the ratio vaporvolume to liquid volume on the ordinate. This curve is a rectangular hyperbolaand shows that 3 gal. of gasoline taken from 1000 cu. ft. of raw gas as a vaporoccupied much less space, per gallon, than did 1 gal. of gasoline taken from1000 cu. ft. of another sample of gas. This is, in general, corroborated byconverting to the same units the residue settlement curves prepared by theTidal Oil Co. and by the Natural Gasoline Manufacturers Assn., though the threecurves, when plotted together, occupy entirely different positions on thepaper, as shown in Fig. 1.
Recent Developments in Flooding Practice in the Bradford And Richburg Oil Fields
Authors: Fettke Charles R.
Published: June 2014

The Bradford and Richburg oil fields are the only pools where artificiallyconducted water drives on an extensive scale have been economically successful.Field practice has progressed from the original accidental or intentionalcircle flood, through the line flood development plan, to the intensivecomplete development plan, which is the most recent and generally considered tobe the most successful. Of the intensive development plan the five-spotarrangement of wells is the one that has been used most extensively. A furtherdevelopment associated with the latter method is the application of additionalhydraulic pressure to that of the hydrostatic head of the column of water inthe intake well. In conjunction with this method is the practice of delayeddrilling of the oil wells until the water from the intake wells has enteredeven the less permeable portions of the sand and developed a "bank" ofoil at which time all oil wells are drilled as nearly simultaneously aspossible. The five-spot pressure flood with delayed drilling gives more rapidreturn on investment than any other method. The seven-spot and nine-spotpatterns are rarely used. No chemicals, such as sodium carbonate and otherso-called flooding agents, are being added to the water at present since thefield tests carried on in 1926 gave no positive results. All air and gas driveshave been discontinued.
Valuation of Flood Oil Properties
Authors: Stephenson Eugene A. , Grettum I.G.
Published: June 2014

THE flooding process was originally the result of accidents to casing andtubing, but it has gradually passed from an accidental condition to a definiteengineering procedure. In spite of the general sheetlike character of the majorsand body, the position of shale bands, their thickness, the size of the grainand variations in effective porosity all give the sand differentcharacteristics in different layers and in different places in the same layer.This condition has an important influence on the movement of flood oil andwater, and on the yield per acre, as well as a bearing on what shall beconsidered the best method of handling flood wells.

A valuation takes into consideration six factors:Flooding methods, of which four have been in common use, as follows, in order of effective recovery,circular flood,line flood,five-spot andfive-spot withdelayed drilling;recovery per acre, which is definitely related to the oilcontent, the porosity, the method of flooding, the spacing program, and thecontinuity of the water supply;the rate of production per well per day, which is definitely related to the method of flooding, the oil content and theporosity of the sands;the operating cost of the well, including royalty, overhead, taxes, etc. (Operating costs are usually expressed as unit cost perbarrel.);the expected price per barrel. It is safer to use the averageprice over a number of years than to attempt to forecast future pricefluctuations.

The discount factor (the sixth factor) used in appraisal of Bradford floodproperties should be less than that commonly applied to other properties, because the hazards of operations have been reduced almost to those of amanufacturing industry.
Variation of Pressure Gradient with Distance of Rectilinear Flow of Gas-saturated Oil and Unsaturated Oil through Unconsolidated Sand
Authors: Cloud W.F. , Norman T.
Published: June 2014

Part I Of Final Report Of A. P. 1. Project No. 33

The data and information compiled under Part I of this report are the resultsof experiments performed in the petroleum engineering laboratory under thesupervision of W. F. Cloud, Associate Professor of Petroleum Engineering andWilliam Schriever, Professor of Physics, University of Oklahoma.

Problems Being Studied

Most of the time has been spent in trying to determine the rate of flow andpressure gradient in a 4-in. flow tube 10 ft. long, which was packed with sandof various grain sizes. To date, only two kinds of sand have been packed inthis tube: 60 to 80-mesh Canadian river sand, 60 to 80-mesh and 80 to 100-meshSimpson sand. The original intention was to follow the same procedure and usethe same types of crude under identical saturation pressures of both air andgas, as well as unsaturated (dead) oil, flowing the various crudes throughseveral different sizes of both Canadian river and Simpson (Wilcox) sands, butlack of time has prevented such an intensive study of the problem.

Some additional time has been spent flowing saturated and unsaturated crudes, similar to those used in the 4-in. tube, through I-in. tubes, one of which was2 ft. long and one 5 ft. long. The results obtained have been checked againstthose obtained by using the 4-in. tube, to obtain the relation of diameter andlength of tube to rate of flow in similar sands.

Laboratory Equipment

Saturation Tank.-A heavy steel cylindrical saturation tank, capacity about 42gal. was mounted on a platform of bricks, then a galvanized tin temperaturebath was built around the saturation tank. This contained

* This paper contains results obtained in an investigation on The Effect ofNatural Gas on the Viscosity, Surface Tension, Adhesion and GeneralExtractability of Crude Oil, listed as Project No. 33 of American PetroleumInstitute Research. Financial assistance in this work has been received from aresearch fund of the American Petroleum Institute donated by John D.Rockefeller. This fund is being administered by the Institute with thecooperation of the Central Petroleum Committee of the National ResearchCouncil. Prof. H. C. George is Director of Project No. 33.
Unit Operation in California, with Discussion of Kettleman North Dome Association
Authors: Jensen Joseph
Published: June 2014

California's outstanding contribution to unit operation is the plan of development now established for the North dome of the Kettleman Hills.Beginning April 1, 1931, the Kettleman North Dome Assn. will control theunified operation and development of 10,800 acres of proven and semi proven oilland, and at the same time the Standard Oil Co. of California will operate asanother unit its fee land of 9460 acres of similar character. The holdings ofthe two companies are in a checkerboard mile-square pattern. In addition tothis, 410 acres of land may yet be included in the Kettleman North Dome Assn.unit and 530 acres of land are definitely out of both units. The owners of someof this land have expressed their intention of cooperating in a reasonable waywith these two units. Cooperative agreements are now in force as to most ofthis field.

Under the definitions of a unit pool and a near-unit pool,! the operation atKettleman Hills will be a near-unit operation, but because of the size of thestructure and its proven highly productive character, the arrangement concludedon Jan. 31, 1931, in the approval of the Kettleman North Dome Assn. Agreementby Secretary of the Interior Ray Lyman Wilbur and by California State Oil and Gas Supervisor R. D. Bush is of outstanding importance to the entire oil industry.

No other major unit operation plans are under way in California at the presenttime. There has been some little discussion of a plan in the North Belridgefield and a feeling that the discovery of oil in the Lost Hills field and alsoin the South Belridge field would necessitate consideration of unit plans. Sofew data are available for these areas, as to the land that should be includedin such unit plans, that little constructive action is now possible. Thebeginning of drilling on the Middle dome of the Kettleman Hills also makes itan area deserving consideration for unit operation.
Repressuring and Initial Pressuring
Authors: George H.C.
Published: June 2014

Since 1911, when J. L. Dunn first used compressed air for repressuringdepleted oil sands in southeast Ohio, the rejuvenation of many depleted oilfields has been directly due to repressuring by means of air or gas.

Developments in repressuring in recent years have resulted in its successfuluse in the early life of some deep, high-pressure oil fields, conserving thenatural gas dissolved in and associated with the oil by returning it to theproducing oil sand after it has been compressed above the existing rockpressure of the reservoir. One of the most successful operations of this typeis that of the Humble Oil &Refining Co., on the DeWalt salt dome atSugarland, Texas.

I quote from a personal communication with reference to this field:

"Structurally, the field is dome-shaped, having a closure of approximately350 ft. Production comes from a sandy shale interbedded with a clean sand andlying over a cap rock which is about 3400 ft. deep on top of thestructure."

A feature of the operation of this field is the production of the requiredamount of oil with the minimum of gas production. Wells on top of the dome havehigh gas-oil ratios, while those down structure have lower ratios, dependingupon the distance of the well from the peak. To date, it has been possible toproduce the oil 'needed from the wells circling the dome above the water zoneand below the gas zone, and in this manner the average gas-oil ratio has beenkept low. The gas from all separators is turned into a gas system which servesthe entire field. From this system, all drilling rigs and utilities requiringgas for a fuel draw their requirements, and the remainder of the gas (abouttwo-thirds of the production) is delivered to a compressor plant which booststhe pressure until it can be returned to the sand at the top of the dome wherethe rock pressure is 1400 lb. per square inch.

"The Sugarland wells produce through 2-in. tubing with a %-in. choke in onewing of the well-head manifold. The pressure builds up as high as 1300 lb. persquare inch on the casing while on the tubing it varies from 0 to 900 lb. persquare inch, depending upon the amount of gas produced with the oil."
Problems in Proration on the Basis of Gas Energy
Authors: Stephenson Eugene A.
Published: June 2014

Critical analyses of the work expended in producing oil by the utilizationof gas energy have appeared in the publications of Shaw,! Pierce and Lewis, andHerold, authors who have ably discussed the factors which must be taken intoconsideration in comparing energy consumed per barrel in various wells whichare flowed by means of gas-lift.

However, two distinct phases of oil production are concerned with the ratio ofgas energy consumed to oil produced. One of these phases is the gas-lift, whichutilizes the differential gas pressures for the purpose of flowing oil, whetherthese pressures be natural reservoir pressures or be induced by artificialcompression of gas or air. The other phase has to do with prorating oilproduction in pools which are operated either as units, or are subject to suchrestrictions as those imposed at Oklahoma City by the Corporation Commission, or by similar controlling groups in other fields. An abundance of literature isavailable relative to the problems of flowing wells by gas-lift, but the firstsuggestion that the energy of the gas within the oil and gas pool might serveas a basis for proration, appeared in the timely article by McWilliams.

Much of the dissatisfaction with proration in certain fields arises becausesome operators feel that besides the hazard to the wells which accompanies thetest, the method of allocating production on the basis of the"potential" gage is inequitable and gives some operators a distinctadvantage over others. The most severe penalty may be exacted from the mostprogressive operators or those who attempt to produce their oil with a minimumquantity of reservoir gas.
Methods and Effects of Unit Repressuring in the Cook Pool
Authors: Crutchfield Graham P.
Published: June 2014

The W. I. Cook pool in Shackelford County, Texas, has been the subject of anumber of papers and articles. Its unique position both as to operation anddevelopment has made it an ideal location for unit repressuring. The majorportion of the pool is located on the W. I. Cook ranch and most of the oilleases are owned by Roeser &Pendleton Inc. and the Continental Oil Co. andoperated by Roeser &Pendleton, Inc. The Humble Oil &Refining Co. andTom James operate producing leases which have a vital bearing on the unity ofthe pool. Both have cooperated in the repressuring project. Practically theentire royalty is owned by Mrs. W. I. Cook and she has given the operators herentire cooperation in all phases of unit repressuring.
Water Problems of the McKittrick Oil Field
Authors: Jensen Joseph , Stevens J.B.
Published: June 2014

The history of the normal oil field is supposed to show an oil graphstarting high in flush production, descending more or less steeply into thecurve of settled production and dropping gradually to the vanishing point ofeconomical operation. Together with this, somewhere in the early history of thefield, there appears from a vanishing point a graph showing the production ofwater. During the period of settled production this graph rises higher and, toward the close, unless extensive work is done in the line of correction, rises far above the oil graph to the point at which the cost of operationterminates profitable pumping. Fields that start out with a high relativecontent of water are generally very short-lived. Fields that never develop awater problem are exceedingly rare.

The McKittrick oil field, Kern County, California, with 840 acres of provedground, 300 wells and a present recovery per acre of 94,598 bbl. from 1898 to Aug. 1, 1930, presents a study which is an apparent reversal of the outlinednormal history. Though the history of the field now covers over 30 years ofoperation, it is still too early and the conditions too unique to project thegraph of production to completion. The present conditions and directions ofchange are most interesting, in that the curve of oil production is remarkablyflat and the curve of water invasion, after reaching an appalling height, hasshown a definite reversal and a continued decline for 10 years.

Early drilling in the McKittrick field was in or prior to 1898. Developmentcontinued steadily to 1918 when the present limitations of the field weredetermined. Shut-offs, according to accepted practice of the time, were made bydriving the shoe into a shale stratum or into a tamped-in bridge of sand, rosinand clay.

Records of early days speak of three waters:surface water which was fresh;an intermediate sulfur water, encountered below the top oil or tar sand;bottom salt water.

In different portions of the field anyone of thesewaters let into a well by faulty completion might require immediate correctionto obtain satisfactory production.