bluuebunny/crossref_metadata_2025 huggingface dataset:
El Segundo Oil Field, California
Authors: Porter L.E.
Published: June 2014

El Segundo field is about 14 miles southwest of the central portion of thecity of Los Angeles, immediately adjacent to the town of EI Segundo and theStandard Oil Company's EI Segundo refinery site. The field is served andbisected by several major highways connecting the beach cities on the west sideof the Los Angeles Basin. The exact location of the field and its position withrespect to other producing areas is shown on the map covering this portion ofthe Basin (Fig. 1).

The Republic Petroleum Co; discovered the first commercial production in thearea when it completed its EI Segundo No.1 (sec. 18, T. 3 S. R. 14 W.) at adepth of 7402 ft. on Aug. 24, 1935, flowing at the rate of about 400 bbl. perday, 28? gravity oil. The producing horizon in this well consists of about 72ft. of conglomerate and schist conglomerate situated below the nodular shale.(Miocene). The true (or solid) schist (Franciscan) was encountered andpenetrated some 20 ft. in the bottom of the hole.

This paper gives a report on the history of development and oil production todate, and also submits the writer's interpretation of structural conditions asdetermined from such development. The limited development, together with thecomplex and variable nature of the producing horizon, makes any interpretationof the structure at present only tentative, and any forecast for a given wellextremely hazardous

History of Oil and Gas Production

The EI Segundo field has produced approximately 1,920,000 bbl. of oil. It has27 producing wells and 14 drilling wells or locations. The present daily rateof production is about 13,400 bbl. The production history of the field to dateis shown in Table 1. The principal companies operating or owning leases in thisfield are: Caminol Company, Geo. F. Getty, Inc., Ohio Oil Co., RepublicPetroleum Co., Pacific Western Oil Corporation, Royalty Service Corporation, Richfield Oil Corporation; Standard Oil Company of California, The TexasCompany, Union Oil Company.
Ten Section Field, Kern County, California
Authors: Wyatt H.T. , Baptie A.S.
Published: June 2014

The Ten Section field is approximately 10 miles southwest of Bakersfield, Kern County, Calif. (Fig. 1). There is no surface evidence of the existence ofthe Ten Section structure, which subsurface exploration has shown to be agently folded, anticlinal dome. Regionally, this field occurs as a fold in thedeeper beds of the gently rolling floor of the San Joaquin Valley. It is on theeasterly slope of the valley, its position with relation to the axis of thissyncline not having been determined.

The field was discovered by Shell Oil Co. with the completion of well Stevens A-I, on June 2, 1936, at a depth of 7888 ft.
Calculation of Equilibria in Hydrocarbon Mixtures
Authors: Buckley Stuart E.
Published: June 2014

The application of hydrocarbon equilibrium data to various problemsencountered in refining and in natural gasoline recovery is an old and wellestablished practice. Both generalized data and data on? specific hydrocarbonsystems have been made available by a number of investigators. More recentlysuch data have been applied to the relations governing the separation of oiland gas both in the reservoir and at the surface. Most of the applications toproduction problems, however,. have been based upon examinations of surfacesamples of oil and gas. This paper describes a technique that has been usedsatisfactorily in a number of cases to calculate directly from the hydrocarbonanalysis of and auxiliary laboratory data on a subsurface sample of thereservoir fluid the behavior of the oil and gas during the various stages ofseparation at the surface incident to production.

Types of Information Calculated

The system of calculations is not designed to supplant field data, but ratherto correlate with them laboratory data obtained under controlled conditions inorder to obtain a more complete and exact picture than usually is possiblethrough the use of field data alone. The chief advantage of the calculations isthe possibility of their use at a minimum of both time and expense to determinecompletely the effect of any possible operating technique upon each of thefollowing:The gas-oil ratio resulting from liberation of the dissolvedgas;the composition and gasoline content of the liberated gas;thecomposition and gravity of the residual oil;the amount and composition of the gas liberated upon flashing the oil from the separator to the stock tank;the shrinkage of the oil in passing from the reservoir to the stocktank.

This information is frequently essential to the correct determination of theadvisability of installing a natural gasoline plant, to design such a plant totake care of seasonal production, and to determine the optimum separatorpressures to carry in various parts of a field.

T.P. 872
Connate Water in Oil and Gas Sands
Authors: Schilthuis Ralph J.
Published: June 2014

Several investigators have reported evidence of the existence of native orconnate water in oil-and-gas-bearing strata. Both water and salt have beendetected in cores of oil sands that yielded oil and gas exclusively whenproduced. Electrical logs often reveal unexpectedly low resistivity through oiland gas sands, indicating the presence of some material that is a considerablybetter conductor of current than oil and gas. Furthermore, calculations of theoil and gas content of reservoirs based upon production and reservoir-pressuredecline data indicate appreciably lower values than are arrived at under theassumption that the pore space is occupied completely by oil and gas.

Origin and Occurrence of Connate Water in Oil-and-Gas-Bearing Formations

The view has been expressed, 1O–15 and is generally agreed upon, that theexpulsion of oil and gas material from source beds and the subsequent migrationand accumulation occurred in the presence of salt water. As the strata thatusually form reservoirs for oil and gas were laid down by, or in the presenceof, ancient seas, the pore space within the strata must have been saturatedwith salt water before the entrance of the oil and/or gas. Thus, theaccumulation of oil and/or gas in the upper regions of structures suitable forreservoirs must have required displacement of the connate watertherefore.

In the absence of any forces other than gravitational, it would be expectedthat the displacement of the connate water out of the zones finally occupied bygas and oil would be complete, and that the vertical distribution 'of gas, oil, and water in a reservoir would be strictly in the order of their densities.Apparently, however, surface and interfacial forces that will not permitcomplete segregation of the fluids are active within the capillary spacescomprising a reservoir. The effects of these forces on both accumulation andproduction of oil and gas have been the subject of study by a number ofinvestigators.

T.P. 869
Influence of Connate Water on Permeability of Sands to Oil
Authors: Dunlap Eldon N.
Published: June 2014

Recently the producing branch of the petroleum industry has shown aconsiderable and growing interest in the quantitative determination of thewater, oil, and gas content of cores as it relates to estimation of reserves, to providing a basis for judging as to the feasibility of applying varioussecondary-recovery and pressure-maintenance processes, and in general to theoperation of producing properties. For years it has been known that oil, gasand water coexisted in the pores of many semidepleted oil measures. It is nowgenerally believed that oil-bearing beds contain connate water in amountsvarying up to 50 per cent of the pore space. However, only lately has reliabledirect evidence of the extensive occurrence of connate water in oil sands beenpublished. Very little work has been done to ascertain the effect of this wateron the productivity and ultimate recovery of oil from wells. It was the intentof this research to study the influence of interstitial water on the flow ofoil through unconsolidated sands, with the hope that the results could beapplied qualitatively to the flow of oil in underground reservoirs partlysaturated with water.

Obviously, ultimate recovery estimates based on the void volume of thereservoir will be in error unless a correction is made for the volume of waterthat occupies a portion of the effective pore volume of the reservoir.Evaluation engineers in the past have applied arbitrary saturation and recoveryfactors that may inadverently have compensated for the failure to considerspecifically the water content. Nevertheless, the evidence available indicatesthat these factors need revising if each is to be independently correct andtruly representative.

Although the fact that the connate water renders part of the pore volume of thereservoir incapable of containing oil is of primary importance to the operator, it is also to his interest to know to what extent the presence of varyingamounts of interstitial water influences the permeability of the sand tooil.

T.P. 874
Flow of Oil-gas Mixtures through Unconsolidated Sand
Authors: Reid L.S. , Huntington R.L.
Published: June 2014

The study of the flow of oil and gas mixtures through oil-bearing formationshas received special attention from the petroleum industry within the past fewyears, and has resulted in a series of research projects based upon variousphases of the flow of heterogeneous fluids through porous media.

Obviously, the low cost of producing oil during the flowing life of a wellmakes it desirable to obtain production by natural flow as long as possible andto effect a maximum recovery of oil and gas by the utilization of reservoirenergy through efficient methods based upon a thorough knowledge of reservoircharacteristics. Despite the extensive research that has been carried out, there is little information available on the behavior of oil and gas mixturesflowing through reservoir formations. This makes it impossible to predeterminethe optimum operating conditions for flowing wells.

A differential pressure must exist in the reservoir in order to induce flowtoward the well. It is a well established fact that with homogeneous fluids therelation of pressure drop to linear distance traveled is a straight linefunction as long as the flow is viscous. However, in regard to gas saturatedoils, a number of investigators have reported that the flow characteristics arematerially altered as some of the lighter hydrocarbons are liberated from theoil to form gas while the fluid passes through the reservoir.

Most of the work done has been concerned primarily with steady-state flow ofliquid-gas mixtures cloud has studied the effects of saturating crude petroleumoils with various gases, together with the resultant pressure gradients understeady flow conditions, noting that unsaturated oils flowed faster and yetmaintained lower pressure gradients than saturated oils.

T.P. 873
Development and Production Problems in High-pressure Distillate Pools
Authors: Foran E.V.
Published: June 2014

Among the many newer disclosures that have accompanied the petroleumindustry's progressively deeper exploratory drilling is the increased frequencywith which the operators are encountering reservoirs of which the products atthe time of discovery exist wholly or predominantly in the gas phase. Thepopular term "distillate pool" is most often used within the industrywhen referring to this type of reservoir, and in this paper the term is used inthat sense. These pools have been observed in many different surroundings. Insome places the entire reservoir is filled with the wet gas containing itswater-white condensible products in the gas phase but apparently with no darkoil or other hydrocarbon liquids in the reservoir. The 8200-ft. horizon in theBig Lake field in West Texas is a good example of this type. At other placesthe wet, or distillate-bearing, gas may form a large gas cap directly overlyingand in contact with an extensive reserve of dark oil. Oklahoma City, KettlemanHills, the 8500-ft. horizon in the Big Lake field, and many others are examplesof this type. There are also many places in which the wet distillate-bearinggas fills nearly the entire reservoir space, while the dark oil occupies only anarrow, band-like zone, which marks the boundary of the reservoir along itslowest productive contour.

The heavier components of these deep pool gases are generally water white incolor, a large portion of which are condensible in a conventional oil and gasseparator, when operated under pressures of the order of 400 to 800 lb. per sq.in. Although the water-white products recovered in the separator sometimes haveend points of 6500 F. and higher on standard Engler distillation, they occuronly in the gas phase in the reservoir. It is entirely possible that even somesmall amounts of dark colored reservoir components may occur in the gas phasewhen the temperature is 3000 F. and pressures exceed 6000 lb. per sq. in. Closeapproaches to these conditions have been encountered in the deepest producingwells. The condensible content of the deep reservoir gases of the many poolsthat have been tested or produced to date shows a wide variation in bothcondensible content, per 1000 cu. ft. of gas, and physical character.

T.P. 1023
The Economics of Overdevelopment
Authors: Gill John D.
Published: June 2014

The purpose of this paper is to invite attention away from the obvious, direct monetary costs of oil-field overdevelopment (as distinguished from"social costs ") to a consideration of the role played by the exerciseof freedom to create even allegedly excessive? plant facilities in contributingto the maintenance of equilibrium in the whole economy and in promotingmaterial progress.

The obvious and most commonly discussed effect of overdevelopment of oilfields is illustrated by the allegation that already the excessive developmentof the East Texas field has cost upward of $162,000,000; in other words, thedrilling of 12,500 wells more than the number estimated as the requirement foreconomical recovery of the reserve has unnecessarily raised the total cost ofdevelopment that amount.

Many other illustrations of so-called excessive development of oil poolscould be presented. Some of them, like Cushing, Powell and Long Beach, might bedrawn from the era antedating widespread discussion in the trade of suchmatters as optimum well spacing, reservoir energy, the conservation rate ofdepletion of reserves, etc. Numerous other cases can be found in the records ofthe current era, which began with the introduction of rationalized restrictionof production. Besides East Texas, there may be mentioned Oklahoma City, Centralia and, more recently, the town-lot development of Bloomingdale, Michigan.

It should be made clear that the author is trying neither to justify norcondone avoidable, uneconomic waste in any function of industry nor todisparage the fullest economic utilization of technical knowledge. The aim isto show the need for a broad view of the economy, including the importantrelationships between its competitive and complementary parts as contrasted toa narrow, provincial view which emphasizes individual gain or loss rather thanthe general good. Moreover, it is only because of a conviction that theconclusions to be drawn from the experience of the oil industry have a wideapplication to industry in general that the author has undertaken to discussthe subject.

T.P. 1084
Exploring Drill Holes by Sample-taking Bullets
Authors: Leonardon Eugene G. , McCann D.C.
Published: June 2014

The search for oil has required, and without a doubt supplies, a tremendousamount of information on the structure, composition, physical properties, andhistory of sedimentary rocks. The earliest and? most complete source ofknowledge is the sample or core of the rock itself, the uses of which are wellknown. The purpose of this paper is primarily to discuss a new method forobtaining these cores, and to illustrate its use in connection with electricallogs.

Most cores have been obtained through a special adaptation of rotary drilling, and the results have been remarkably good, considering the mechanical problemsinvolved. Unfortunately, because of the time and expense, this method cannot beused for the entire length of the drill hole. Even though ingeniouscontrivances have been evolved in order to reduce the time spent in roundtrips, such as wire-line coring equipment, mechanical coring still remains tooexpensive to be carried out continuously. In practice, therefore, one isfinally compelled to estimate the probable depths of the more interestinghorizons and, allowing a wide margin of safety, to core through those sectionsonly. It is true also that interesting results have been obtained by examiningthe cuttings brought to the surface by the mud circulated in the well duringthe process of drilling. Be that as it may, the inescapable fact remains thatkey horizons may be passed inadvertently, for one reason or another, while thedrilling operations are being performed. The only continuous record of theformations encountered is that furnished by electrical surveys.

Obviously, it would be desirable to make the electrical survey first and totake the samples from the wall of the hole according to the indications on theelectrical log. In this way, it would be possible to core only the exactsections desired, eliminating the otherwise inevitable estimates as to thepoint at which to start coring, and thereby reducing to a minimum thisexpensive operation. At the same time this method would provide a maximum ofuseful samples.

A device for taking samples of the formation from the walls of a hole thereforeoffers the possibility of recovering cores from zones otherwise lost as asource of this type of information.

T.P. 1062
Gravitational Concentration Gradients in Static Columns of Hydrocarbon Fluids
Authors: Sage B.H. , Lacey W.N.
Published: June 2014

Variations in the composition of the liquid phase of natural reservoirswhich are continuous through significant ranges in elevation have been noted bypetroleum technologists. In general, there is a greater gas-oil ratio and thegravity of the oil is higher in production from the upper parts of theformation. In the present paper the possible changes in composition withelevation which would result from the attainment of thermodynamic equilibriumin a uniform gravitational field have been evaluated for a naturally occurringhydrocarbon liquid, a binary hydrocarbon liquid phase and a binary hydrocarbongas. The results indicate a progressive decrease in the mole fraction of thecomponents from methane through the butanes with increasing depth, accompaniedby a corresponding increase in the amount of the heavier components making upthe system. The magnitude of these variations is perhaps insufficient toexplain completely the variations in the properties of the liquid phase thatare encountered at various elevations within a particular producing horizon.However, the changes are significant and the treatment presents an example ofthe application of thermodynamic data to the evaluation of the properties ofhydrocarbon fluids under the conditions approaching those encountered innatural reservoirs.

Theoretical Considerations

Muskat has discussed the work of earlier authors relating to the equilibriumrelationships of multicomponent systems in a gravitational field. He alsopresented explicit solutions for several cases and discussed the physicalsignificance of gravitational concentration gradients.

In engineering work it is customary to consider the pressure, the temperatureand the composition of a phase to be the independent variables sufficient toestablish its state.

T.P. 1004
Physical Properties of Hydrocarbons and Their Mixtures
Authors: Gilliland E.R. , Lukes R.V. , Scheeline H.W.
Published: June 2014

Knowledge of a large number of the physical properties of the hydrocarbonsis needed in the calculations and studies of the production engineer. Sinceexperimental data on these properties of the individual hydrocarbons and theirmixtures are available in only ~ relatively few cases, the use of generalizedcorrelations has developed rapidly in the last decade. The generalizedcorrelations of pressure, volume and temperature, enthalpy, and vapor-liquidequilibria, on the basis of reduced temperatures and pressures, are outstandingexamples of this development. These correlations are of particular value to theproduction engineer interested in the flow of oil and gas, since they can beused to estimate the conditions under which segregation of phase occurs as wellas the composition, density, al).d relative amounts of the phases. Thetechnique of using the correlations for such estimations has been published byseveral authors and will not be considered in this paper. A considerable numberof data have been obtained to check the generalized pressure-volume-temperaturecorrelations, and these data indicate that such relations hold for thehydrocarbons from methane to heptane. The accuracy is in general sufficient formost engineering pressure volume-temperature calculations. However thegeneralized correlations of enthalpy and vapor-liquid equilibria have ingeneral been developed from the pressure-volume-temperature correlations bythermodynamic calculations and only a relatively few experimental data areavailable to check these calculated values. The calculations from pressure, volume and temperature are likely to lead to large errors in the calculatedenthalpy and vapor-liquid equilibria. Thus, in the calculations of enthalpies, slopes of the pressure-volume-temperature data are employed, and determiningthese slopes can greatly amplify small errors in the original data. In thevapor-liquid equilibria calculations it is necessary to have the pressurevolume-temperature relations of the mixture, and the latter properties are muchmore questionable than those of pure components, particularly in the criticalregion.

T.P. 1060
Interfacial Tension between Water and Oil under Reservoir Conditions
Authors: Hocott C.R.
Published: June 2014

The distribution and movement of fluids in oil reservoirs are influenced toa great extent by capillary forces, which depend upon the size and shape of thepores in the reservoir rock, the surface characteristics of the rock, and theinterfacial tension between the fluid phases. This paper presents the resultsof an investigation of the interfacial tension between salt water and crude oilcontaining dissolved gas under reservoir conditions.

Apparatus and Procedure

In the preliminary phases of this investigation, it was found that a scumformed at the oil-water interface, which made measurement of interfacialtension by either the ring or capillary rise methods unreliable. Accordingly, the drop-weight method, in which a fresh interface is continuously formed, wasselected. In this method, a tip through which drops of one fluid can beexpelled is immersed in a second fluid. At the instant that the drop becomeslarge enough to fall, the gravitational force tending to pull away the dropexactly balances the interfacial force tending to hold it. From the size of thedrop, the dimensions of the tip, and the density of the two fluid phases, theinterfacial tension may be calculated.

The apparatus consists of a circulating pump for bringing the oil toequilibrium with gas at the desired pressure, a displacement pump for formingthe drops, an interfacial tension cell in which the drops are formed, and adensity cell to determine the density of the oil. The density of the water isdetermined separately in another apparatus. A flow diagram of the assembledequipment is shown in Fig. 1.

The interfacial tension cell contains a stainless-steel dropping tip suspendedfrom the top and extending below the surface of the oil. The tip is acylindrical rod with a small hole in the center through which the water wasforced to form the drop on the lower face.

T.P. 1006
Surface Chemistry of Clays and Shales
Authors: Garrison Allen D.
Published: June 2014

The chemistry of clays and shales has been assuming increasing importance inthe petroleum industry, and two factors have greatly influenced this trend. Thefirst has been the growing evidence that the marine shales are source beds, andthat the petroleum compounds have migrated to the sand reservoirs overlying orunderlying these shales: the second has been the demand for drilling fluidsbetter adapted to penetrate these marine shales without difficulty andexpense.

Origin and General Composition of Clays and Shales

Clays, shales and surface soils are all closely related materials. They aremixtures of finely divided compounds formed during the weathering of the solidcrust of the earth. Their nature is essentially colloidal; that is, theirbehavior is determmed by the state of division of the materials and the surfacereactions of the smallest grains. Many of their chemical changes affect onlythe exposed areas and do not involve the interior of the grains of matter. Theextent of these reactions is more nearly proportional to the area of thesubstances than to their mass therefore it is possible for a small amount of amaterial in an extremely fine state of division to completely dominate thecharacter of the mixture.

More than 83 per cent of the crust of the earth is composed of threeelements-oxygen, silicon and aluminum. Consequently, the corrosion products ofthe crust are predominantly aluminosilicates, or compounds of aluminum, siliconand oxygen.

If we add the compounds of six elements-iron, calcium, sodium, potassium, magnesium and hydrogen-more than 98 per cent of the crust has been accountedfor. These six elements, together with the first three, also appear in soils, clays and shales.

But direct chemical analysis is of little value in describing the nature ofsuch materials. Many chemical individuals may be present in variable amounts, and the extreme subdivision of anyone of the individuals may contributequalities that dominate the mixture.

T.P. 1027
A Resume of the Application of Gravel Packing to Oil Wells in California
Authors: Clark W.A.
Published: June 2014

The production of sand in an oil well increases operating costs because ofabnormal wear in subsurface equipment, the necessity for frequent cleanouts, and the need for a means of disposing of the sand. Moreover, removal of sandfrom the zone can bring about the creation. of cavities from which bodies offormation, sand or shale, may slough into the hole, endangering the shutoff, impeding production or collapsing the liner. The procedure known as gravelpacking is attracting attention as a means of controlling these factors andcontributing to the productive life of a well. That gravel packing is nowsubstantially beyond the preliminary stage on the Pacific Coast is reflected inthe 191,000 bbl. of oil produced monthly by the 66 gravel-packed wells in 11 different producing sectors.

Reasons for Gravel Packing

Gravel packing, if properly carried out, can be expected to provide the following benefits:Prevent the movement of sand and thus eliminate sand production and sandfills, and prevent the formation of cavities.Provide a practical, relatively inexpensive, large-diameter hole, which willprovide well-known theoretical advantages.Support the walls of the hole by completely filling the space between theliner and the formation, regardless of its irregularities, and afford a supportfor liners.Provide for more efficient pumping operations in wells by:possiblyutilizing the gravel as a gas trap in pumping gaseous fluids,allowing deepsubmergence of the pump into the oil zone.

In a conventional well-that is, where the liner is set in an open hole-? eventhough perforation sizes are chosen according to known rules based on analysisof sand grains from samples from the zone, there is likely to be someproduction of sand.

T.P. 1079
Radial Filtration of Drilling Muds
Authors: Williams Milton
Published: June 2014

It is generally recognized that fluid is lost from rotary drilling muds topermeable strata during normal drilling operations; but that this fluid is thefiltrate from the mud, rather than the mud itself, has been shown by variousworkers.

The presence of this filtrate in oil-bearing or gas-bearing strata isundesirable and harmful. The decreased permeability of the stratum to oileffected by the presence of water has been pointed out by severalinvestigators, and since, in the production of the reservoir fluid, thegreatest pressure drop occurs immediately adjacent to the borehole, it followsthat infiltered water is particularly objectionable in this region. Again, thisfiltrate tends to make electrical logs less reliable, since oil in theproximity of the borehole is probably flushed out to an appreciable extent bythe water Observation of side wall cores may be misleading for the same reason.Drill-stem tests in low-pressure areas may be of doubtful value where no oil isrecovered, unless sufficient time is allowed for production of water lost fromthe mud. The infiltered water may hinder drilling operations by softeningshales and causing sloughing; the "tight hole" occasioned by excessivedeposition of filter cake in the hole is a common occurrence. The filter cakeremaining on the face of the producing formation may itself sometimes bedetrimental to production.

In view of these implications of the importance of filtration of mud, aninvestigation was undertaken to determine the factors involved in theinfiltration process, and to correlate these in such a manner that the valuesobtained in routine filter tests employing a conventional filter of the"wall-building tester" type, together with data on size of hole, drillpipe, and rate of mud circulation, could be used to estimate water loss anddistance of penetration of the filtrate into strata.

Quantitative relations of filter-cake permeability, filtrate viscosity, andrate of filtration have been developed for filtration in the simple laboratoryfilter.

T.P. 1112
Temperature Surveys in Oil Wells
Authors: Millikan C.V.
Published: June 2014

Temperature measurement in wells is an old practice and geothermal gradientshave been of interest to geologists for many years. Their application to theoperation of oil wells is a more recent practice. It has long been recognizedthat temperature anomalies occur in drilling and producing wells butthermometers that could obtain a satisfactory record of the anomalies were notavailable.

The normal geothermal gradient is considered as being about one degreeFahrenheit for each 60 ft. of depth. This "normal" gradient varies indifferent areas, but whatever it may be in an area there is little variationfrom the surface to as deep as the drill penetrates. The normal gradient isappreciably changed by gas expanding from the reservoir into the borehole or bythe movement of fluid through a borehole while drilling, producing, orcirculating. It is the resulting anomalies and abnormal gradients from whichconditions in wells can be interpreted. Some of the applications of suchinterpretations are locating the position of oil or gas sands, permeable stratain a reservoir zone, gas-oil contact, source of water, casing leaks, and thetop of cement behind casing.

Thermometers

A thermometer for use in wells must be sensitive and have a low thermal lag.The sensitivity should permit recording 0.2?F. or less for differentialtemperatures although the actual temperature need not be more accurate thanIOF. The thermal lag should be as low as rugged construction will permit in order to allow surveysto be made in a minimum of time. Of the several kinds of thermometers, theserequirements are most easily obtained with the vaporpressure, expansion, andelectric-resistance types. Thermometers for use in wells may beself-contained-that is, the complete instrument is lowered into the well and arecord made of the temperature---or the thermal element only may be loweredinto the well and the temperature recorded at the surface. The vapor-pressureand expansion types are more adaptable for a self-contained instrument whilethe electricresistance thermometer is more suitable for surface recording oftemperatures.

The self-contained instrument can be run against high pressure on a single wireline with only one operator required. The instrument and its hoisting equipmentis easily portable and can be mounted on a small car. The disadvantages are asomewhat greater thermal lag and the necessity of completing a run before anytemperature or temperature anomaly is known.

A surface-recording thermometer has the advantage of being somewhat moresensitive and of having a lower thermal lag.

T.P. 1258
Colloid Chemistry of Clay Drilling Fluids
Authors: Loomis A.G. , Ford T.F. , Fidiam J.F.
Published: June 2014

It is only within the past 10 years that serious attempt appears to havebeen made to improve rotary drilling fluids by the application of theprinciples of colloid chemistry, although the use of chemicals to control therheological properties of clay slips has long been known in the ceramicindustry. The main difficulty apparently lay in the lack of a complete analysisof all of the functions of a drilling fluid in the drilling of the well, together with the lack of adequate consideration of how colloid science couldbe applied to secure these ends, and particularly how apparent antitheticalproperties of the fluid could be compromised. Thus one analysis1 of the manyrequirements of a drilling fluid proved conclusively that the viscosity shouldbe low, in order that cuttings and entrained gas might be eliminatedefficiently in the settling ditch, while the loss in carrying capacityaccompanying low viscosity could be regained by increasing either the densityof the mud or the upward velocity of the mud stream in the annular space of thewell, and the danger of sticking of the drill stem due to rapid settling incase of enforced suspension of drilling operations could be eliminated byenhancing the thixotropic properties of the fluid.

The desired properties of the drilling fluid having thus been established, itwas a natural step to treat the fluid with viscosity-reducing chemicals, suchas salts of weak organic acids- for example, sodium tannate or gallate-and toadjust the pH to the alkaline side to such a degree of thixotropy as would give low viscosityand low yield point under the conditions of flow prevailing in the settlingditch, but rapid gelation and high yield point when quiescent in the annularspace during shutdowns. In fact, flow in the settling ditch should be justshort of turbulent while flow in the well, together with the flow of mud pastthe cuttings, is practically always turbulent. The use of chemicals other thanthose mentioned, such as Calgon (sodium hexametaphosphate) and certain otherphosphates together with sodium tannate, has now become standard practice andit is the consensus that this method of treatment has proved to be an importantstep in the development of the art of drilling oil wells.

It is safe to assume that the application of colloid chemical principles canalso help in solving other outstanding problems of drilling fluids, such as thedevelopment of cheaper and more efficient viscosity reducers; the developmentof chemicals that do not lose their effectiveness in a short time duringdrilling operations; the finding of chemicals to preserve the plasteringproperties of muds when concentrated brines are encountered or in drillingthrough salt beds; improvement in the plastering properties of poor muds byfurther deflocculation, and, conversely, the prevention of excessivedeflocculation of certain marine shales sometimes encountered; the preparationof muds suitable for the successful drilling of heaving shale formations; thefinding of chemicals to treat the mud to prevent or to diminish lostcirculation;

T.P. 1201
A Chart to Provide Approximate Correction for Temperature and Deviation from Boyle's Law
Authors: Brokaw Albert D.
Published: June 2014

The accompanying chart was devised to provide a rapid and simple method ofcorrecting for temperature and compressibility (deviation from Boyle's law) ofgas under relatively high pressures and temperatures, such as are encounteredin many deep reservoirs.

The chart was prepared by interpolating for the desired values in theexperimental data of Burke and Keyes and Kvalnes and Gaddy on thecompressibility of methane, after adjusting their results from 0?C to 60?F andcombining the correction factors for compressibility and temperature into asingle multiplier, which, applied to the product of pressure and reservoirvolume, gives at once the volume at one atmosphere (14.7 lb. per sq. in. abs.)and 60?F. The relationship of this multiplier to the compressibility factor Z, as used in most discussions, is simply:

(Equation)

where Z is the compressibility factor and T the absolute temperature(Rankine).

Fahrenheit temperatures are shown on the vertical axis and pressures inpounds per square inch absolute on the horizontal axis.

Correction factors or multipliers at intervals of 0.05 from 0.55 to 1.4?have been plotted on the chart and are calculated to give volume of gas at oneatmosphere pressure (14.7 lb.) and 60?F. The operation is as follows: Thereservoir volume, times the number of atmospheres pressure, times themultiplier, gives the volume of gas measured at one atmosphere (14.7 lb. persq. in.) and 60?F.

For example, a reservoir is estimated to have a volume of 10,000,000 cu.ft., bottomhole pressure is 2940 lb. per sq. in. and temperature is 184?F.

To make the correction for methane, follow the 184? line horizontally to the2940-lb. pressure line. The intersection lies between the 0.85 and 0.90correction lines, and by interpolation we may estimate the multiplier at0.863.

T.P. 1375
A Preliminary Report on the Application of the Mass Spectrometer to Problems in the Petroleum Industry
Authors: Hoover Herbert , Washburn Harold
Published: June 2014

This paper is in the nature of a rough preliminary report on the progressthat has been made in the application of the mass spectrometer to variousproblems arising in the petroleum industry. A few years ago the authorsconsidered a number of the problems that were arising in the qualitative andquantitative measurement of small amounts of hydrocarbons. The methodsavailable of making analyses by chemical techniques appeared to leave much roomfor improvement. Without going into the reasons at this point, attention wasturned to the possibility of employing physical instead of chemical methods ofaccomplishing the desired results.

A preliminary investigation disclosed that the mass spectrometer presented apossibility of solving many problems which could not easily be accomplished byother methods. Work was begun in developing the necessary apparatus andtechnique. A great deal of encouragement and many valuable suggestions werereceived from Dr. Robert A. Millikan, Dr. W. R. Smythe, and

Dr. W. N. Lacey, of the California Institute of Technology, and from Dr. E. O.Lawrence, who recently received the Nobel Prize, of the University ofCalifornia. The authors particularly wish to acknowledge the very greatwillingness of these outstanding scientists to be helpful in solving many ofthe problems that were involved.

So far as the authors are aware, this was the first application of the massspectrometer to commercial work. The results were considerably better than hadat first been anticipated. Briefly, it is possible to run a qualitative andquantitative analysis of an unknown mixture of hydrocarbon gases, with anaccuracy of better than plus or minus 5 per cent of each of the variousconstituents. An exceedingly high degree of sensitivity has been obtained, anda relatively short time is required to complete an analysis. Furthermore, it isunnecessary to separate a mixture of gases into its various' components inorder to complete the analysis.

The Mass Spectrometer

The mass spectrometer should not be confused in any way with the optical orgrating type of spectrograph now in general use. The operation of the massspectrometer is entirely different in principle and bears practically noresemblance to the optical or grating instruments.

The original conception and development of the mass spectrometer dates from andis generally credited to Aston, of Cambridge, England. An early accomplishmentof his research, about 20 years ago, was the discovery that the inert gas neonwas actually a mixture of two kinds of atoms, one of the atomic weight 20 andthe other of atomic weight 22. These two components occurred mixed in suchproportion as to yield the usual atomic weight of 20.2.

T.P. 1205
Chemical Treatment of Bentonitic Suspensions and the Relationship to the Heaving-shale Problem
Authors: Power H.H. , Houssiere Charles R.
Published: June 2014

The development of effective and dependable methods for drilling through theso-called "heaving-shale" horizons, particularly in the Gulf Coastarea, is believed to comprise a major contribution to drilling technology, andto the task of finding and developing our undiscovered oil pools. Manymechanical remedies have been proposed and are in use in troublesome areas forcombating heaving shale. However, in conducting a research program it wasconcluded that the physical and chemical properties of shales should beinvestigated, and the effect of added chemicals on such properties determined.As a preliminary step, the effect of chemicals on bentonitic suspensions wasdetermined in accordance with recent contributions in the field of ceramics.The most plausible theoretical explanations for the behavior of the clayminerals involved are offered in the paper that follows. It is hoped thatsubsequent investigation of actual shale from troublesome wells will be aidedby the initial work done on bentonitic suspensions of known composition.

Introduction

Formations variously designated as "heaving shale," "sloughingshale" and "caving shale" impede and may even preclude drilling ofoil wells, particularly in certain parts of the Gulf Coast. In a previous paperit has been stated that the development of effective and dependable methods fordrilling through these troublesome beds is believed to comprise a majorcontribution to drilling technology, and to the task of finding and developingour undiscovered oil pools.

Since the attack on the heaving-shale problem by mechanical means wasprincipally a matter of field investigation, it was concluded that a researchprogram should be concerned with the physical and chemical properties ofheaving shales, and the effect of added chemicals on such properties. It wasrealized that a study of shales required an advanced knowledge of the behaviorof the individual clay minerals. A thorough review of the literature led theauthors to the conclusion that very recent contributions in the field ofceramics furnished the most plausible theoretical explanations for the behaviorof clay minerals. Accordingly, these fundamental ideas will be used in anattempt to explain the behavior of more complex systems whose composition andreplaceable ions are known.

T.P. 1401
Equilibrium Constants for Hydrocarbons in Absorption Oil
Authors: Webber C.E.
Published: June 2014

The economical recovery of the valuable constituents from the effluent ofgas-condensate wells has developed into a problem of balancing the cost ofrecovery against the cost of compressing the residual gas back into theformation. A possible method of extracting the gasoline and distillate from thenatural gas is by oil absorption at high pressures. In order to design andevaluate an absorption plant, fundamental data on the composition of thecoexisting hydrocarbon vapor and liquid phases at various temperatures andpressures are essential.

A review of the literature indicated that the necessary data for the design ofsuch plants are lacking. The nearest approach to desired published data is thatof Katz and Hackmuth, who experimentally determined the composition of thecoexisting vapor and liquid phases in a natural gas-crude oil system atpressures up to 3000 lb. per sq. in. and at temperatures from 40? to200?F.

This paper presents the results of the experimental determination of theequilibrium distribution of the hydrocarbons methane through hexane betweennatural gas and a typical absorber oil. The ranges of temperature and pressurechosen were from 33? to 180?F. and from 100 to 5000 lb. per sq. inch.

Materials

The absorber oil was a typical naturally occurring, straw-colored distillatethat had previously been steam-distilled to an initial boiling point of 300?F.The physical and chemical properties, including the results of an Englerdistillation, are presented in Table I. A large volume of this oil was obtainedand it was used throughout the complete set of experiments.

The n-hexane was obtained from the Ohio Chemical and Manufacturing Co., Cleveland, Ohio. This liquid had a boiling range of from 149? to I52.6?F., witha density of 0.667 at 60?F. and a molecular weight of 85 by benzenefreezing-point depression. The propane, isobutane, n-butane, isopentane andn-pentane were obtained from the Philgas Department of the Phillips PetroleumCo. Certified analyses of these compounds showed their purity to be in excessof 99.5 per cent and they were not further purified.

T.P. 1252
A Plan for Operation of the Paloma Field
Authors: Geis W.H.
Published: June 2014

The following pages summarize the causes that led to the suggestion of unitoperation of the Paloma field, the organization of committees, preparation ofthe Paloma Operators Agreement and the reasons for rejection of the plan.

Introduction

Long ago an Austrian physicist observed that under certain conditions thecondensation of a liquid from gaseous mixtures resulted from pressurereduction. Some 50 years later he would have known that his research was not invain. He would have seen a group of serious operators and engineers seeking toapply that principle to a conservation program for unitized production in thePaloma gas field - but he would also have been saddened to see that forcesunsympathetic to the application of science in oil production, with little orno appreciation of modern methods and the advantages of cooperation, so farhave prevented the adoption of that program.

Soon after the Paloma field was discovered it was realized that all thehydrocarbons in the reservoir existed in the gaseous phase. This condition wasconfirmed over a large area. Therefore, if the field was to be properlyexploited with the greatest ultimate recovery of condensate, the hydrocarbonsin the reservoir must be produced in the single or gas phase. They must becautiously extracted with the least possible reduction of the naturalpressure.

If this could be accomplished, or if artificial pressure control wereutilized, the condensation and underground loss of the valuable distillatewould be preventable - otherwise it would not be.

Wholehearted cooperation of all operators was required in order toaccomplish the conservation purposes of the program. To this end the productionengineers of the several companies concerned lent their time and talents. Theyfully investigated the physical relationships of the products within thecomplicated gaseous mixture, prepared extensive reports on the subject and drewup a reasonably efficient plan of operations, which now is commonly called the "Paloma Unit Plan" but actually was entitled "The Paloma OperatorsAgreement."

All of the engineers were not in perfect agreement on all the features ofthe plan, or even on all the engineering principles. However, it is safe to saythat on all the important or essential factors there was a unanimity ofopinion, particularly as to the objectives. These were fairly simple and reduceto one controlling item, "pressure control" by cycling orrecycling.

T.P. 1472