bluuebunny/crossref_metadata_2025 huggingface dataset:
Approved Drilling and Production Practice in Oklahoma and Kansas
Authors: McWilliams J.R.
Published: June 2014

The task of recovering most of the contents of an oil and gas reservoireconomically presents many and varied problems. In order to attemptintelligently a solution of these problems, an understanding of fundamentalphysical laws is essential. As the pertinent facts needed in applying theselaws to recovery problems are not readily obtainable, observation must be madeand the data tabulated. Here, good judgment must be exercised, for at best theinformation is meager.

The engineer is well fitted to undertake the task of solving this problem.In my opinion, the decision on the part of some production executives to allowthe engineer to cope with the oil recovery situation and other problems is anoutstanding example of improvement in production methods. The executive headmust make this decision or the qualified engineer will be working under asevere handicap with the present system of supervising the production of oiland gas.

A qualified engineer should have not only the required technical trainingbut also enough field experience to enable him to understand the difficultiesencountered in producing oil and gas. Such a man tactfully cooperating with thepractical oil man can greatly improve present methods of oil recovery. Therealization that Nature's forces have not been efficiently controlled in pastrecovery of petroleum deposits has recently brought distinct improvement inproduction methods.

Papers are to be presented at this meeting discussing in detail improvedmethods of conserving gas in both flowing and pumping wells, and also methodsof lifting oil after Nature's supply of gas has proved inadequate. Theapplication of back-pressure to producing oil wells has not, to my knowledge, been extensively applied in Oklahoma or Kansas up to the present time. Most ofthe flowing wells are allowed to flow through the casing until the rockpressure has been dissipated. However, some flowing wells have been tubedbefore the well stopped flowing through the casing. Recording pressure-gagescan be installed to study well performance.
Development and Operations in the Panhandle Field
Authors: Bennett E.O.
Published: June 2014

In the Texas Panhandle one of the greatest difficulties of operation is theparaffin situation. Oil in that, field ranges from 83? up to about 90?, as itexists in the sand. It is from 2900 to 3000 ft. deep, and should be up around120 to 150?, as compared to other oils in the United States. Furthermore, theoil in the Panhandle congeals to a solid ball of wax at from 55 to 60?, whichgives a margin on an average of about 20?, to get oil from the sand into thepipe lines or points of use.

Gas Pressure

The gas pressure in the Panhandle field is about 420 lb., which is abouthalf the hydrostatic head. It is not sufficient to flow the wells that we termthe flow wells in the Panhandle. They are not what I would call flow wells, because if you shut in one of them and open it up again the well is dead, andit is necessary to swab or agitate the gas with the oil to make it come back.The oil in most of the so-called flow wells is produced in a spray form. Thegas factor is extremely high and there is an enormous amount of gas in thefield which has been wasted.

It is estimated that the original supply of gas was about 120 quadrillionfeet. In other words, there was enough gas in the Panhandle originally to runthe State of Texas for 166 years, if the gas were consumed every day of theyear at the rate of the peak load in Texas during the closing month of theyear. The gas is in a lime above the main pay. It varies from nothing up to 500ft. thick at different points in the field. Between the big gas and the pay itvaries from nothing up to 150 ft., which in one part of the field is in a limeand in another part of the field in a granite wash. There is a shale breakwhich varies from nothing up to 100 ft. or thereabout. It is different indifferent parts of the field.

It is impossible to drill in this gas with the hole loaded. Unhydrated limeis put into the hole and then water. The water slackens down the unhydratedlime and sticks the tools in the hole. For that reason they are unable to use arotary.

We at present, and others I believe, are working on a method of trying todoctor this solution, so to speak, to enable us to drill with a hole loadedwith fluid and to save the gas. At the present time I estimate that 100 millioncubic feet of gas is wasted in the Panhandle daily.
Production Engineering in 1927
Authors: Umpleby J.B.
Published: June 2014

Production engineering in 1927 may be characterized by a great clarificationof fundamental conceptions, and many improvements in technique. During the yearthe profession has received marked recognition by the industry and to an extentnever before attained has become an integral part of it.

History

Petroleum production engineering is a new profession. Prior to 1925, whenthis Institute undertook the work, no forum existed for the open discussion ofits technical problems. There was no attempt at a handbook of the subject priorto "Petroleum Production Methods" by J. R. Suman, in 1921, and notextbook prior to "Petroleum Production Engineering" by L. C. Uren, in1924. As late as 1926, only six schools and universities offered specialcourses in petroleum production engineering. Prior to about 1923, engineersengaged by oil companies were used almost exclusively for construction andlocation work. Two of the leading production engineers in the Mid-Continentfield, although with their respective companies more than twelve years, werenot definitely assigned to production work until 1924. Both men now head largedepartments giving almost their entire time to production problems.

Because of the newness of the profession, the leading production engineersof today have had their fundamental training in mining, civil, mechanical andelectrical courses. Not unlikely this diversified, training is in considerablepart responsible for the amazing growth of the profession. I believe, however, that recognition is due principally to economic pressure within the industrywhich has directed attention more and more sharply on costs and efficiency.After all, the justification for the growth and continued development of theprofession is to recover more oil from a given unit of sand at less cost perbarrel.
Mechanical Installations of the Gas-lift in Texas Outside the Gulf Coast Region
Authors: Foran E.V.
Published: June 2014

There are many factors which control the ultimate production of oil and gasfrom a producing formation and the rate at which this production is obtainedfrom any of the producing wells in the formation. The most important of these, and the one over which the greatest control can be exercised, is thedifferential pressure existing between the formation and the well bore. Inproducing any well by means of the gas-lift, it may be possible to change theflow tubing in a number of ways or vary the volume of circulating gas or airused for flowing the well, but if these operations, regardless of theirmagnitude, do not change the differential pressure between the producing sandand the well bore, they will in no way change the production of the well. Ifthis statement is accepted as a fact, then all gas-lift or air-liftinstallations should be designed with but one object in view; namely, a meansby which we can economically control very wide ranges of differential pressuresbetween the formation and the well bore.

Factors of Production

In gas-lift production from any given formation, there are four majorfactors which govern the magnitude of the differential:the depth of thewell;type and size of flow tubing;volume of the circulating air orgas, andphysical properties of the oil-gas mixture after it has reachedthe well.

The first of these factors is uncontrollable and does not vary. Theother three are controllable within certain limits.

The degree to which the last three factors can be controlled will entirelygovern the length of life of the well while on the lift, the lifting cost, andthe daily production. It will also govern to some extent the ultimateproduction from the wells or leases producing by this method. These fourfactors will be discussed in detail in another part of this paper.

Before proceeding further, a review of the present general practice inTexas, elsewhere than in the Gulf Coast region, will be given.
Air-gas Lift Practice in the Seminole Field
Authors: Shaw S.F.
Published: June 2014

The Seminole field was first drilled in 1913. During the next 10 years otherattempts were made to discover oil in this field, but without encouragementuntil March, 1926, when the Indian Territory Illuminating Oil Co. completedNo.1 Dyer in the Hunton lime for 1100 bbl. On July 16, 1926, theIndependent-Garland interests discovered oil in the Wilcox formation when No.1T. Fixico came in at 4055 ft. and on Sept. 9, 1926, production reached a peakof 8040 bbl. On Aug. 1, 1927, the daily production of the pools making up theSeminole district amounted to slightly over 500,000 bbl., practically all ofwhich was coming from the Wilcox formation.

The Hunton formation has not been very productive of oil, but has maintaineda fairly high gas pressure; this formation has been encountered at from 3800 to4200 ft., below which there is about 100 ft. of Sylvan shale. The shale isunderlain by 75 ft. of Viola limestone in a few places in which formation oilhas been encountered. Below the Viola lies the Upper Simpson formation in whichis found the Wilcox sand. The depth of the Wilcox in the Seminole field variesfrom 3900 to 4500 ft., and initial production has reached as much as 12,000bbl. The gravity of the oil is about 410 Be.

The general practice is to set 6 5/8-in. casing above the Wilcox and drillin, though in several cases 5 3/16-in. casing has been set for the oil string, and in a few instances, casing as small as 4 3/4 in. has been employed.
General Discussion on the Air-gas Lift
Authors: Porter H.P.
Published: June 2014

The papers presented at this meeting contain a great amount of valuableinformation. Wonderful progress has been shown in the development of air andgas-lifts. There has been nearly everything brought out that touches upon thesubject. The real point that is lacking is exact knowledge of the velocitywithin the flow column which will produce the best effect - that is the thingwe must know more about.

Velocity in Gas-Lift Flow

In other lines of industry the matter of velocity of fluids in pipe lineshas been well analyzed and there are known laws by which to calculate velocityof flow; for instance, in irrigation work large pumps are designed with intakepipes to employ an intake velocity of 4 ft. per sec. By reduced cross-sectionthe velocity is increased rapidly as it enters the pump and the discharge rateis at 12 ft. per sec., which in turn is reduced in the discharge column to 4ft. per sec. Crushed coal, grain and granular material is found to be bestconveyed by air when a pneumatic conveyor is employed at 100 ft. per sec. As inthe design of a pumping plant or a pneumatic conveyor, the velocity at thelower end of the column in the flowing well must be controlled within certainlimits for best results.

Mr. Griswold, I believe, stated that they had velocity as low as 15 ft. persec. and from that up to 75 ft. per sec.

Mr. Pierce and Mr. Lewis showed an ideal flow column showing how thevelocity increased as the fluid was carried up the column, but did not give anyfigures as to the velocity. It would be well to take that sort of a diagram toestablish an ideal velocity at the lower or intake end, and then calculate thevelocity from expansion of the gas as it goes up. It may be that the idealintake velocity would vary, depending on the depth of the well, the quantity ofliquid to be handled or the pressure which it may be desired to hold. Thesubject, is one that might be worth much research.
Use of Electricity in the Mid-Continent Field
Authors: Johnson D.L.
Published: June 2014

Only general treatment of a subject of such scope can be given in a shortpaper, therefore, except in a few instances, statistics and descriptions ofspecific installations are omitted.

The earlier applications of electricity to the production of petroleum inthe Mid-Continent field were widely separated chronologically, each holding aspecial interest, and each contributing greatly to the present development.

Electric Pumping

One of the first installations of electric pumping was on a lease nearJenks, Okla., in the Arkansas River bed, where a difficult problem was solvedby the use of motors. The Arkansas River had frequent flood periods whichinterfered seriously with the use of jacks and pull rods. Small piers werebuilt with old casing used as piling, and upon these were set small jacksdriven by 3-hp. squirrel-cage motors. The starting switches were located on abank and the power was furnished by a small generator, which was driven by anoil country gas engine. This installation was made in 1913 and is, I believe, still in satisfactory operation.

In 1914, the Cushing field came in and the Hill Oil &Gas Co.electrified its Shamrock property, using eight-pole Star Delta motors, rated at10 to 30 hp. and belted through countershafts to the band wheel. Power wasfurnished by a small generating plant consisting of two 135-kw. machines, gas-engine driven. Considerable difficulty was experienced in the earlyoperation of this station because of low voltage. It is characteristic of smallalternating-current generators that voltage regulation will be poor with widelyfluctuating loads. This field had three producing sands, and a number of wellswere redrilled with the motors, and this, together with a great deal ofswabbing, was responsible for the bad load conditions.
Problems Encountered in Handling Panhandle Crude
Authors: Vietti William Victor , Oberlin William A.
Published: June 2014

Crude petroleum produced in the Texas Panhandle oil field is both an asphaltand a paraffin-base oil and is further characterized by being a high-gravitycrude with an extremely high cold test. An eight-well composite of Panhandlecrude showed the following characteristics:

Gravity, 36.6? A.P.I.

Viscosity: 61 sec. Saybolt at 100?F., 170 sec. Saybolt. at 75?F., 1560 sec.Saybolt at 50?F. (stirring)

Cold Test, 60? F.

Subsurface Conditions

The original pressure in the formation in the Panhandle field closelyapproximated 420 lb. gage or 435 lb. absolute pressure. Temperatures takenindicate that the formation temperatures do not exceed 90? F. The temperaturesin Table 1 are typical measurements taken on one lease.

(Table 1 - Temperatures in Panhandle Wells)
Summary of Repressuring Experiments in California Fields
Authors: Bell A.H.
Published: June 2014

The results of repressuring (or gas-drive) have been very encouraging to theseveral companies doing experimental work along these lines in California. Themost notable examples are the Shell and the Union Oil companies at Dominguez, the Marland Oil Co. at Seal Beach, and the California Petroleum Corpn. at SouthMountain.

The results of the Marland test at Seal Beach are interesting in thatrepressuring was started while several wells were still flowing; also, onaccount of the high pressures required to overcome the hydrostatic pressureexerted by high-head edge water.

The well first chosen for repressuring is about halfway up the flank of thestructure and had been on the beam making about 250 bbl. of fluid daily, cutting about 60 per cent. emulsion. The fluid level was 230 ft. from thesurface and the top of the sand was 4393 ft. Tubing was run to 4000 ft. with apacker and the space above the packer was filled with water to balance the highpressures.

Gas was started in slowly to allow the fluid to be pushed back into thesand, and required three days at a pressure of 1500 lb. per sq. in. beforestarting into formation. The pressure was once built up to 1800 lb. and thecompressor was shut down for a few hours. When again started, the well took gasat 1500 lb., and after about three weeks the pressure was dropped to 1450 lb.The present pressures required range between 1400 and 1450 lb. Volumes as highas 1,500,000 cu. ft. per 24 hr. were put into the well.

Increases as high as 50 per cent. in production were obtained in wells up-structure with very little increase in wells down-structure. Also, the watercut on one edge well materially decreased. After about 40 days the repressuringwas moved to two wells farther down-structure and the well originallyrepressured was put on production. The result of this was a great increase inthe production of wells one location farther down-structure, a rapid increasein one well one location up-structure, and a decrease in production of thewells farthest up-structure. Later the gas started to short-cut to the nearestwell down-structure, nullifying to a certain extent the effects of therepressuring work.
Ten Years Application of Compressed Air at Hamilton Corners, Pa., with Core Studies of the Producing Sand
Authors: Fettke Charles R.
Published: June 2014

In 1914, the officials of the Brundred Oil Corpn., faced with the problem ofintroducing new methods to increase production in the old and nearly depletedpools of Venango County, became interested in the Smith-Dunn (Marietta) processwhich was at that time being tried out in southeastern Ohio and which wasalready yielding very encouraging results. A license to use the process inPennsylvania was secured from the owners of the patents. These patents werelater declared invalid.

The method was first used in Pennsylvania on a property consisting of about434 acres, of which 300 are productive, at Hamilton Corners, 15 miles northwestof Oil City, in Cherry Tree and Oakland Townships, Venango County. Theproducing horizon is the First Sand of the Venango Group. A small oil pool wasopened up in this vicinity in 1904. By July, 1916, when the compressed air wasfirst introduced to restore pressure, the production had dropped to a pointwhere it was no longer possible to continue profitable operation. From thattime until March, 1927, over 100,000 bbl. of oil have been recovered from thetract. The property is being operated at present by the Brundred Oil Corpn. andLux. The 1926 production, amounting to 10,650 bbl., was only 400 bbl. short ofthe maximum reached during any year of the 10-year period that the process hasbeen in operation.

Inasmuch as the Hamilton Corners pool is the first one in Pennsylvania inwhich the Marietta process was tried out, and the one in which it has beenlongest in continuous operation, considerable interest attaches to the resultsobtained.

Through the courtesy of H.D. Brown and W.J. Brundred, officials of theBrundred Oil Corpn., all their data on this operation were made available tothe writer in connection with an investigation of rejuvenation methods in theState for the Pennsylvania Geological Survey.
Factors Influencing the Recovery of Petroleum from Unconsolidated Sands by Waterflooding
Authors: Uren L.C. , Fahmy E.H.
Published: June 2014

During recent years, oil producers have observed with interest the practicalsuccess which has attended the application of water as a medium fordisplacement of oil from its reservoir sands in the Bradford field of northernPennsylvania and southern New York. Here, according to various authorities, additional recoveries of from 2,000 to 12,000 bbl of oil per acre have beensecured by this method, after ordinary flowing and pumping methods ofproduction had practically reached the lower limit of economic operation.

Notwithstanding the success which has attended the practical use of theflooding process in the Bradford field, oil producers in other regions areskeptical of its value when applied under physical conditions differingmarkedly from those which characterize the Bradford field. Its use wouldprobably be construed as illegal in most of the oil-producing states. Thisgeneral reluctance on the part of oil producers in other regions to accept theflooding process is due in large part to lack of information regarding thefactors that influence its operation and efficiency.

With the purpose of clarifying to some extent the issues involved, and ofdetermining when the flooding process may or may not be effectively employed, the writers have conducted as series of laboratory experiments under carefullycontrolled conditions, designed to indicate the influence of various physical, chemical and lithologic factors.
Deep-Well Drilling Technique
Authors: Dievendorff H.H. , Hertel F.W.
Published: June 2014

The method of drilling deep wells into the earth for the recovery of oil andgas is beset with many hazards. This is especially true in the Ventura Avenuefield, which has the distinction of being the hardest field in California inwhich to complete a deep well. The hard, shifting and squeezing formations mustbe penetrated to great depths in the face of tremendous gas pressures. Thisfield presents problems that keep the operators abreast with all of the latestdevelopments in oil-field tools and machinery and in oil-well drillingpractices. Equipment must be strong, and adapted to deep-well drilling and thehandling of long heavy strings of casing. High-pressure sands require theutmost care and attention of the operators and no chances can be taken, since aserious blowout may cause the loss of a well that has cost months of labor andexpense. Equipment must meet these requirements or be discarded.

Although the deepest wells in the world are not in this field, nor have thelongest strings of casing been set, nevertheless, the consistency with whichdeep wells are drilled and long strings of casing are set places the VenturaAvenue field foremost, in this respect, among the oil fields of the world. TheVentura Avenue field does claim the deepest commercial oil-producing well inthe world, in the Shell Co. of California's "Edison" No. 18. This wellwas drilled 7015 ft. and came in flowing 3280 bbl. of oil per day. This fieldalso claims the deepest average depth of producing wells in that its 111producing wells average 5676 ft. in depth. Of these 111 producing wells, 50 are6000 ft. or deeper, and 16 are 6,100 ft. or deeper. Also, of the 111 producingwells 100 are flowing, and 11 are pumping wells.

This paper is intended to set forth the methods used in the drilling of deepwells with rotary tools and the handling of long heavy strings of casing in theVentura Avenue field.
Rotary Drilling Problems
Authors: Cartwright R.S.
Published: June 2014

Rotary Drilling Controls

Two types of automatic drilling controls, the Halliburton and the Hild, arenow available and are coming into more or less general use in deep drilling.The primary function of both is to maintain a safe limit of torque on the drillpipe, this being accomplished by automatically controlling the weight orpressure on the cutting tool. Neither type will necessarily increase drillingspeed, but by permitting advantage to be taken of "breaks" in the holehigher average cutting speed may be maintained. The control is essentially asafety device, and should be considered as such.

It is not the purpose of this paper to discuss the merits of drillingcontrols, although the advantages over manual feed at the brake drum areobvious, but rather to point out some of the limitations.

The Halliburton Control

The Halliburton control is designed to operate during drilling through theagency of the draw works. Automatic and constant control of the torque on thebit is governed by clutches on the control itself, and the line shaft to drumshaft drives on the draw works. In operations other than drilling the controlis simply a jackshaft between prime mover and draw works. It is, of course, adaptable to any type of power.

Because control of the torque on the bit is dependent on the various ratiosor clutch combinations available on the Halliburton control and the draw works, it follows that there are certain limitations in points of control. Table 1shows the possible ratios which can be obtained with the control and a populartype of three-speed draw works, it being assumed that the highest possible gearcombination - the combination which when engaged will suspend the least amountof weight - has a value of 1.00.

According to the table there are "blind spots" in the series. Thisis true particularly among the lowest ratios, which are most used to suspendthe major part of the weight when great depths are reached.
Underground Surveys of Oil Wells
Authors: Anderson Alexander
Published: June 2014

In many oil fields a great variation in the production of adjoining wellshas long been observed, and a certain proportion of dry holes, situated betweenprolific producers, has been regarded as normal without thorough investigationas to cause. Similarly, an occasional prolific producer has been found in apart of a field where all other holes have proven disappointing.

Adjoining wells which showed an unreasonable difference in production havebeen surveyed, and the bottom of the poorest producer has been found to havelost sufficient vertical depth, through its drift, to diminish seriously itspenetration in the oil zone. Again, the bottom of the good producer has beenfound to be more favorably situated by its migration up structure.

Surveying of wells in California fields has shown many instances where thedry hole has drifted far off the structure to such a degree that no amount ofdeepening could ever convert it into an oil well. In other cases, edge wellshave been found to drift into the field.

At this time, in California, the surveying of oil wells is beginning to beaccepted as a routine part of operating procedure. Some operators are surveyingall of their new wells and, in some of the recently discovered fields, thispractice is providing invaluable assistance in methodical development.

The information that has been obtained from the surveying of many wells hasconvinced most operators that it pays to give careful attention to the drillingof wells. Crews are now usually cautioned to avoid reckless competition witheach other. Whereas, formerly, certain companies demanded a large footage fromtheir drillers, they now issue orders that a very moderate speed in drillingshall be maintained and that every care be taken to avoid practices likely tocause excessive deviation of the hole from vertical. As a result of these newinstructions to drilling crews, a distinct decline in the average drift of thewells drilled by these operators has taken place and fewer dry holes are beingdrilled from good locations.
Pressure Control of Oil Wells
Authors: Griswold E.H. , Wilkins W.J.
Published: June 2014

Pressure control of oil wells may be defined as the adjustment of pressures within a well to obtain the most efficient and economic utilization of the natural gas energy with a minimum of sand troubles or irregular water encroachment. The purpose of this paper is to present the methods used by the writers in applying pressure control and a discussion of the various effects occurring within the wells affected. The benefits to be derived from the conservation of natural gas energy have been so adequately discussed and demonstrated in prior papers by various engineers that the effects on ultimate production will not be discussed other than to mention a few representative cases. The detrimental effects of irregular edge-water encroachment and of sanding up are of general knowledge to the industry.

Effect on Ultimate Production

One of the strongest objections voiced against pressure control is that of the danger or inadvisability of deferring oil production by cutting the rate of production. It has been our experience that such deferred production is returned within a few weeks or months rather than years and that an increased cumulative oil production is obtained in the early life of the well by conserving the natural energy. In many cases the rate of production is increased rather than decreased by the adjustment of pressures to obtain the minimum gas factor.

Fig. 1 shows the history of a Wilcox sand well in northern Oklahoma, which was pressure-controlled from completion. It is noted that during the early months while flowing naturally through the casing the gas factor was decreased rather than allowed to follow its natural tendency to increase. A string of 2 1/2-in. tubing was run to restrict the flow and resulted in a decreased gas factor with a more sustained rate of production. When first placed on gas-lift the gas factor again tended to increase, but after the proper pressure adjustments were made, remained approximately steady. It was necessary to defer 100 bbl. per day of oil production in order to maintain this low gas factor.
Measurements of Original Pressure, Temperature and Gas-oil Ratio in Oil Sands
Authors: Sclater K.C. , Stephenson B.R.
Published: June 2014

Recent progress in oil-recovery methods has brought into prominencegas-energy relations in oil sands. The greater the effort made to utilize thisgas-energy relationship to the best advantage in oil recovery, the greaterbecomes the need for more precise information concerning physical conditions asthey actually exist in an oil well.

The intelligent use of gas-oil ratios when considering production efficiencyhas been the subject of much recent discussion. It has been stressed that thepressure as well as the volume of gas must be known when considering theefficiency of a producing well on an energy basis. When methods of productionare compared on an energy basis it implies a knowledge of pressure, temperatureand physical properties of the fluids at the bottom of the well.

In questions concerning gas-lift and the pressure control of wells usuallythere is a wide variance of opinion among engineers when energy relations comeup for discussion. Perhaps this difference of opinion can be traced toerroneous assumptions made with regard to the physical conditions existingwithin the well. If erroneous assumptions are made it follows that computationsbased on these assumptions will give results which also will be in error.

That erroneous assumptions are made is not to be wondered at because whenhandling a fluid composed of gas and oil, we are dealing with a complexity ofhydrocarbon components each varying to some degree in physical and chemicalproperties. This means that the physical state of the gas and oil will dependnot only on temperature and pressure but that it will be influenced also by therelative amounts of the various hydrocarbon components present. If water ispresent the problem becomes still more complicated.

From these considerations alone it would appear that we can well afford togive some thought to devising more positive methods or means for obtaining dataon physical conditions within the well rather than depend entirely oncomputations from casinghead data.
Back-pressure Control of Flowing Wells
Authors: Miller H.C.
Published: June 2014

The energy stored in the compressed natural gas absorbed in or otherwiseassociated with the oil in reservoir sands is usually the most important factorin oil recovery. It is recognized that hydrostatic pressure and gravity may aidmaterially in the drainage of oil, but in the early life of the majority offields the principal source of propulsive energy is the expansive force of thegas associated with the oil. Since gas is admittedly the most important factorin the production of oil, its control so as to produce the maximum amount ofoil with the minimum amount of gas will be reflected in increased oil recoveryfrom reservoir sands. Controlling the gas means regulating its expansion sothat the velocity of flow of oil through the channels in the reservoir sands isneither so great that frictional resistance becomes excessive nor so slow thatthe gas, because it can travel more rapidly than oil through the irregularpassageways in the sands, will by-pass and reach the well without doing usefulwork in bringing oil from the sands.

Oil and gas flow from the reservoir sands to the well because of differencesin pressure. The rate of flow is dependent upon the differential pressuresexisting in the sands and in the well. By altering the amount of back-pressuremaintained on the well this differential pressure can be regulated and changedfrom a maximum (well flowing "wide open") to a minimum when there willbe no flow. Oil and gas flow through the irregular channels in reservoir sandsat different rates mainly because of the fact that one is a liquid and theother a gas. Therefore, because oil and gas have different characteristics offlow, application of back-pressure changes the rates of flow with relation toone another so that wide variations in gas-oil ratios are possible. Obviously, the formation gas energy will be utilized most efficiently when a unit of gasdelivers the maximum amount of oil to the well.
Analyses of Waters of the Salt Creek Field Applied to Underground Problems
Authors: Ross J.S. , Swedenborg E.A.
Published: June 2014

Oil-field waters enter into many underground problems with which thepetroleum engineer has to deal. Whether the problem is one of infiltration ornatural encroachment, it is always desirable to determine the source of thewater before commencing repair or remedial work. The usual mechanical tests fordetermining the source of extraneous water in wells are slow and expensive. Anexcellent means for the identification of oil-field waters may be afforded bytheir chemical characteristics when the chemical character of waters from thevarious sands has been established by careful sampling and analysis cautiouslyinterpreted.

In the Salt Creek field, Wyoming, a fairly high degree of efficiency hasbeen attained in the control of field operations by utilizing the informationafforded by the analysis. All of the operating companies appreciate this meansof identifying waters, with the result that water-sampling has become generalpractice. Most of the chemical work dealing with Salt Creek waters has beendone since the laboratories of the Midwest Refining Co. and the U. S.Geological Survey, were established in the field; the former in 1922, thelatter in 1924. A spirit of cooperation has existed between the company and thegovernment personnel by which many of the data for this paper were madeavailable.

Sands of the Salt Creek Field

The principal sand horizons in the Salt Creek field are the Shannon, First, Second, and Third Wall Creeks, Dakota, Lakota, Sundance and Tensleep. Of thesethe important oil producers are the First Wall Creek, Second Wall Creek, Lakotaand the Sundance. The Third Wall Creek is lenticular and is productive in onlya few wells in the southern end of the field. There are also a number of shalewells, but they do not produce water in any appreciable amount.
Oil Recovery Investigations of the Petroleum Experiment Station of the U. S. Bureau of Mines
Authors: Mills R. Van A. , Chalmers Joseph , Desmond J.S.
Published: June 2014

Problems Being Studied

The selection of the first problems to be studied was based largely upon thefollowing very practical questions asked by several of the largest operators inthe Mid-Continent field.What are the causes for the formation of excessive amounts of bad thick oilon properties that are being repressured with compressed air and how can thistrouble be prevented?Why, in some areas, does the oxygen in the air injected into an oil sandduring repressuring operations apparently change to carbon dioxide? Is carbondioxide formed by the oxidation of some of the oil in the sand? How can theformation of inert or low B.t.u. casinghead gas, loaded with nitrogen, carbondioxide and oxygen, be prevented?What percentage of the oil originally present in an oil sand can berecovered by the ordinary methods of operation when the gas originallydissolved in the oil is the main propulsive agent?What percentage of the amount of oil produced by ordinary methods can berecovered under average conditions by repressuring a so-called depleted oilsand?What are the relative propulsive efficiencies of compressed air and naturalgas in repressuring operations?What are the practical advantages of pressure maintenance and earlyrepressuring as compared with late repressuring?
Mathematical Development of the Theory of Flowing Oil Wells
Authors: Versluys J.
Published: June 2014

When a well strikes an oil-bearing layer, the oil has a pressure which isgenerally sufficient to enable it to rise to near the surface (sometimes abovethe surface). As soon as a well begins to produce, however, the liquid movesthrough the pores of the reservoir bed and the pressure in the well becomesmuch lower than the pressure originally prevailing there. At some distance fromthe well, however, the pressure in the reservoir bed remains unaltered; thusthe pressure of the oil has not only to lift the oil, but also to overcome thefriction resistance in the pores. The fact that so many oil wells are gushersis a consequence of the energy accumulated in the gas.

In gushing the well acts as a gas-lift. A mixture of liquid and gas (the latterpartly dissolved in the former) rises vertically from the oil-bearing layerthrough a cylindrical casing to the surface. In time conditions alter and thewell ceases to gush regularly, then the gushing can be further promoted byinserting a narrower tube in the well and connecting the top of the oil stringto the tubing. If the action in time becomes irregular, the gushing can be keptup for a further period by forcing gas between the two tubes. In the oil fieldsthe term" gas-lift" is used actually only where extraneous gas isapplied, as in the last of the stages mentioned. The action, however, is justthe same whether the gas exclusively originates from the formation, or ispartly applied artificially. Thus by gas-lift we simply mean a vertical tube inwhich the energy of gas under pressure, and of dissolved gas, is utilized forraising a liquid.

In gushing oil wells the pressure is frequently very high and the absorptioncoefficient 0.4 (expressed in vol. ratio) of the coexisting gas is notparticularly high, so that in reality it should be assumed that a considerableportion of the gas, at any rate at the bottom of the gas-lift, is dissolved inthe oil. For water-producing wells this is not usually of such importance.
Modern Practice in Water-flooding of Oil Sands in the Bradford and Allegany Fields
Authors: Torrey Paul D.
Published: June 2014

The water-flooding of oil sands has been widely practiced for many years inthe Bradford and Allegany fields. Its effect upon the production of thesefields has been almost phenomenal. In 1907 their estimated production was 3500bbl. per day; in December, 1929, the combined production is estimated at 33,000bbl. per day, an increase of almost 1000 per cent. in 22 years. This increasein production is directly attributable to the successful application ofwater-flooding, which has transformed the fields that were rapidly approachingabandonment into one of the most actively operated regions associated with thepetroleum industry, and has made them important factors in the production ofPennsylvania Grade crude oil.

The writer is indebted to many companies for information included in thispaper. He is particularly grateful to the Sloan and Zook Co., the PetroleumReclamation Co., George Bovaird, Jr., and the Associated Producers Co., ofBradford, Pa., who have generously made available much valuable data. Owing tothe frequently competitive and confidential nature of property purchases, ithas not always been possible to make specific reference to individual wells orproperties; but wherever feasible, specific references have been made.

Economic Factors

The successful application of water-flooding for increasing the recovery of oilhas been almost confined to the Bradford and Allegany fields. This has been duenot only to legal restrictions in other fields and to very favorable sandconditions in the Bradford-Allegany region, but also to certain economicfactors which are worthy of consideration.

There has been some alarm regarding the effects of the rapidly increasingproduction upon the oil market but the writer is inclined to believe thatfuture development can be made sufficiently flexible to meet the demand forthis grade of oil. There has been a decided tendency toward consolidation ofproperties by mergers and purchases and, in addition many of the individualproducers are content to take advantage of floods advancing on their holdingsfrom adjoining properties without developing their own on an intensivescale.
Mechanics of a California Production Curve
Authors: Herold Stanley C.
Published: June 2014

Only two years ago there appeared in our technical magazines articleswherein it was shown that the application of back-pressure increased theultimate production of a well, that edge water can be stopped in itsencroachment by the injection of gas into the productive formation, with theconsequent conservation of energy within the pool, that gas is the source ofall energy involved in oil production, and that each pool has a definiteminimum-valued gas-oil ratio to be attained for the most economical operationof wells. Today we are not so certain of these matters. Probably in somefields, under special circumstances, these ideas are correct, but certainlythey must not be correct in all fields, under any and all circumstances. Thenature of the productive structure, the location of particular properties onthe structure, the existence of adjoining neighbors, whether these are higheror lower on the structure, and the methods of production followed by alloperators on the structure, sand for sand on depth, make these subjects worthyof full consideration.

Our difficulties in analyzing and comparing the performance of reservoirs invarious parts of the world do not rest solely upon structural features andproperty lines. We do not complete the list of causes for these difficulties ifwe add lithologic features and correlation of strata encountered by the drill, with the magnitude of pressures exerted by fluids within any of these strata. Afurther cause, one which the author believes will complete the list, is oneinvolving the theoretical mechanics of fluids within porous formations-porousin the nature of interstices in sandstones and some limestones, networks offractures in shales, and cavities in otherwise compact limestones.

The confusion of ideas concerning reservoir mechanics still with us today seemslargely due to our failure to recognize among all wells three great divisionsof theoretical mechanics, three great systems which are distinct in themselves, and according to which each well, or better, each group of wells, must beanalyzed separately. These systems have been named by the writer HydraulicControl, Volumetric Control and Capillary Control, respectively.
Superhard Metals for Tool Facing
Authors: Morgan Harry J.
Published: June 2014

One of the greatest improvements in drilling equipment has been the developmentof hard facing metals which are welded by electricity or by acetylene to form afacing which protects the steel of the bit from abrasive wear. The maindesirable characteristics of hard facing metals are resistance to abrasivewear, resistance to shock and perfect bond with underlying metal.

Resistance to abrasion offered by various metals shows many anomalies. Compounds containing carbon, silicon and boron are the most important hardsubstances. Carbon, as diamond, silicon carbide and especially the carbides ofiron, chromium and tungsten are the outstanding hard products in common use.Tungsten carbide is probably the most commonly used. It is made in the electricfurnace and it is important to get the right amount of carbon and the correctcrystalline structure in order to obtain the greatest hardness and greatestresistance to abrasion. It may be obtained in three main divisions: wrought, cast and casehardened.

Insert hard metals are common. The method of application varies, but it isgenerally welded to the bit, placed in channels or in drilled holes and coveredwith a hard surfacing metal. Robinson has given a very complete article on the use of inserts. Gregg and Kiittner has discussed themetallography of tungsten carbides and given a good bibliography of thesubject.

The time and expense of large-scale testing, together with variations inresults, led to the development of a laboratory testing machine for determiningthe abrasive-resisting qualities of different metals.
Law of Flow for the Passage of a Gas-free Liquid through a Spherical-grain Sand
Authors: Schriever William
Published: June 2014

Law of Flow for the Passage of a Gas-free Liquid through a Spherical-grainSand

The flow of a gas-free liquid through a spherical-grain sand has beeninvestigated by Slichter. By theoretical considerations involving a ratherlarge number of approximations he arrives at the following flow-formula:

v = CPd2At

NLB(1-m)

where V is the volume of liquid delivered in time t through a cylindricalcolumn of sand of length L and cross-sectional area A by a pressure-drop P whenthe sand grains of diameter d are packed to a porosity m and the coefficient ofviscosity of the liquid is n. C and B are constants which were determined fromgeometrical relations; B was in reality a function of m. Values of B(l - m) forvarious values of m were given in a table.

In the same Annual Report of the U. S. Geological Survey, King reported theresults of his experiments on the flow of water through porous media. He foundthat there was a departure of about 86 per cent. from a linear relationshipbetween rate of flow and pressure, for a specimen of Dunnville sandstone forpressure drops not exceeding 60 cm. of mercury. The specimen was approximately4 cm. in diameter and 5.1 cm. in length. Over the same range of pressure hefound a departure of 45 per cent. for a specimen of Madison sandstone. Forunconsolidated sands he found departures as great as 49 per cent. for pressuredrops of 70 cm. of mercury; for pressure drops not exceeding a few inches ofwater he obtained a close approximation to a linear relation.

*This paper contains results obtained in an investigation on The Effect ofNatural Gas upon the Viscosity, Surface Tension, Adhesion and GeneralExtractability of Petroleum of Various Types, listed as Project No. 33 ofAmerican Petroleum Institute Research. Financial assistance in this work hasbeen received from a research fund of the American Petroleum Institute donatedby John D. Rockefeller. This fund is being administered by the Institute withthe cooperation of the Central Petroleum Committee of the National ResearchCouncil. Prof. H. C. George is Director of Project No. 33.
Cementing Problem on the Gulf Coast
Authors: Wilde H.D.
Published: June 2014

At the Sugarland and Raccoon Bend fields in the Gulf Coast area, all wellsare drilled with rotary tools and the casing is always set in cement that isplaced by the circulation method. After the cement is set, the rotary mud thatfills the hole is not withdrawn or bailed out; consequently, it is notcustomary to give the cementing job a direct test either by putting pressure onthe hole to see whether the cement will hold or by observing whether aneffective water shut-off is secured.

About three years ago, this company started the practice of coring the cementleft in the bottom of the casing and examining the core thus secured. If thecore was hard and strong, the cementing job was judged a success but if thecore was incoherent, soft, and crumbly, the job was considered a failure. Ofcourse, there were intermediate types of cores and it was not always a simplematter from this examination to decide whether the job was a success orfailure. After about two years, a summary of the core examinations that hadbeen made indicated that of cementing jobs made at depths of 1000 ft. or less,60 per cent. were failures; of those between 1000 and 2000 ft., 80 per cent.were failures, and of those between 3000 to 6200 ft., 100 per cent. werefailures. This startling table emphasized the need of the study of theconditions under which the wells were cemented and of adopting means to reducethe percentage of failures.

In addition to these core tests, two wells gave direct evidence that thecementing jobs were not always successful. In one, a four-year-old well atGoose Creek, the casing was perforated, and when fluid was circulated some ofthe old cement was brought to the surface. Most of it was powdery and the fewchunks that were brought up were soft and crumbly. The other was a well at Raccoon Bend which during a blow-out brought a number of chalky, soft andcrumbly pieces of cement to the surface.