bluuebunny/crossref_metadata_2025_split huggingface dataset:
Principles of Unit Operation
Authors: Oliver Earl , Umpleby J.B. 
Published: June 2014

It is believed that in connection with the study of unit operation by thePetroleum Division of the A. I. M. E. a review of the simple principles of unitoperation would be helpful. To that end, the following discussion is submitted.It is not to be considered in any sense as the conclusion of the committee, butrather as material submitted for its consideration and represents at this timeonly the viewpoints of its authors.

Growth of the Oil Industry
In 70 years the oil industry has grown from a single well on Oil Creek, VenangoCounty, Pennsylvania, producing 25 bbl. per day, to more than 400,000 wellsscattered over five continents with a daily output of 4,000,000 bbl. In thattime petroleum has expanded from its simple use as a medicine in a fewlocalities to a multitude of diverse uses in homes of every country the worldover. During those years the oil fields of the United States have producedtwo-thirds of the world's output and have shipped their excess production intoalmost every country.
In those years several hundred thousand good wells in the United Statesdeclined into small ones and depleted shallow deposits gave way to deep zones;so that the United States crude oil industry gradually changed from one of lowcost production to one of higher cost. Throughout its entire life it haslabored under two serious economic disadvantages, namely, constantly recurringperiods of demoralization through overproduction, and competitive developmentmethods that are wasteful.

Development of Foreign Competition
During the transition from low to higher cost production in the United States, events even more significant were taking place in foreign lands. Jungles weretamed and deserts conquered.
Some Development and Operating Economies of Unit Operation
Authors: Harlan Sam 
Published: June 2014

At intervals during the past several years the oil industry has beenconfronted with the problem of forestalling crises in its affairs. These criseshave been reduced to periods of depression which, fortunately, the industry hasbeen able to survive. Under the existing competitive practices which controlthe producing division of the industry it apparently has been proved that thebest efforts logically to curtail development and producing operations areinadequate for effecting a true production balance and the consequentstabilization of prices. The industry is awakening to the fact that thesituation warrants revolutionary thought and at this time it is looking for apermanent solution of its problem in a general plan for unit development andoperation such as the one first proposed by Henry L. Doherty. Mr. Doherty'sproposal was designed not only as a means for stabilizing the industry as awhole, but its principles involve very definite potential benefits for theaverage individual operator and royalty owner as participants in pooledprojects. The benefits to these individuals would be derived from maximumrecovery, the maximum utilization of natural energies, the minimization ofdevelopment and operating costs, enhanced values of leases and royaltiesthrough improved efficiencies and ultimate yields, improved earnings throughstabilized crude oil prices, etc. This plan was revolutionary to the industry'spractices and at the time was rejected, but it now appears that the developmentand operating policies for new properties are continually approaching the idealof the original plan.
Oil companies are constantly extending their efforts to improve all factorsthat have a bearing on the costs and efficiencies of their operations.
Mid-Continent Practices in Handling Flowing Wells
Authors: Bond Reid W. , Trax D.L. , Watson C.D. , Walker Morgan 
Published: June 2014

Common practice in the Mid-Continent until recently was to prolong thenatural flow of oil wells as long as possible by agitation and then swab for ashort period until the well was put on the pump. Comparatively recently thegas-lift has superseded the swabbing and agitating period and in some casesencroached on the natural flowing life, particularly where it was evident thatthe potential oil capacity of the well was greater than the gas supply, orlifting medium.
The majority of wells are finished with either 61/4, 6 5/8 or 81/4-in. casingand connected to a separator through a flow line which is usually 6% in. Theflow line is generally designed to eliminate sharp turns and has reduced thegas-oil ratio and therefore increased the efficiency in a good many instances.Until recently all wells were allowed to flow without restriction against thepossible trap pressure until it was deemed advisable to put them on gas-lift.This resulted in a fairly efficient flow during the early life of the well ifthe well was rather large but was usually inefficient in small wells and in thelater flowing life of large wells, on account of the large area in the casingand therefore excessive slippage.
Recently, considerable effort has been made to increase the efficiency of smallflowing wells by running tubing to eliminate as much slippage as possible. Withlarge wells there is a considerable trend toward back-pressuring, or beaning tofind out whether it is possible to reduce the gas-oil ratios and increase theflowing life.
The greater number of fields that have been back-pressured have been producedin that manner through necessity, either to restrict production for prorationpurposes or, in fields producing by hydraulic pressure, to reduce waterencroaching. The recent Cromwell sand development in Little River is an examplewhere both back-pressuring by means of high-pressure traps and beans andflowing through tubing were used to conserve gas, reduce the high gas-oil ratioand prolong the flowing life.
Electric Welding of Field Joints of Oil and Gas Pipe Lines
Authors: Price Harold C. 
Published: June 2014

Abstract
Prior to Sept. 1, 1928, there had never beenconstructed what might be termed a long pipe line with electric-welded fieldjoints. A year later more than 2500 miles of electric-welded lines had beencompleted which varied in diameter from 6 to 20 in., and in length from 50 to 700 miles. This paper discusses methods used on five lineswith a total length of about 750 miles. The welding equipment used for thefiring line or rolling welds, was 300-amp. generators driven with six-cylindergasoline engines, and for the bell-hole or tie-in welds, 200-amp. generators driven by four-cylinder gasolineengines. A welding gang consisted of a foreman, 6 to 12 firing-line welders and2 to 4 bell-hole welders, a mechanic and a tractor driver.
Coupons about 1/4 in. thick were frequently cut fromcompleted welds, which showed a cross-section of the weld and an indication ofits size and penetration. For tests of tensile strength complete welds were cutout. The tensile strength of 52 welds cut from 420 miles of 12-in. lineaveraged 50,870 lb. per square inch.
The following results give a fair average of the numberof welds made per man per day: on 157 miles of 8-in. line both firing-line andbell-hole welds averaged 15.3-the firing-line average was 21; on 39 miles of10-in. line the firing-line average was 19.9; on 50 miles of 6-in. line, withunfavorable weather, the average was 17.7; on 424 miles of 12-in. line most ofwhich was welded during the spring, 10.3, and with good weather the average rose to 13 welds per day. The average time for making a complete weldon 12-in. pipe 0.313 in. thick was found to be 30 min. for the rolling weld and45 min. for tie-in welds.
A comparison of costs between electric and gas weldingshows that the cost of labor for electric welding is 25 per cent. more thangas, generating cost 61 per cent. less than gas, welding wire 40 per cent. lessthan gas, and supervision and overhead the same.
Recent Studies of the Recovery of Oil from Sands
Authors: Chalmers Joseph 
Published: June 2014

The Petroleum Experiment Station of the U. S. Bureau of Mines atBartlesville, Okla., has for the past three and a half years maintained alaboratory with the necessary personnel for conducting research on methods ofincreasing the recovery of oil. Some of the preliminary problems encountered instarting this work, with the data obtained, were discussed in A. 1. M. E.Technical Publication No. 144, "Oil Recovery Investigations of thePetroleum Experiment Station of the U. S. Bureau of Mines," which waspresented at the October meeting of the Institute at Tulsa, Okla., in1928.

Scope of Paper
The following discussion gives some of the results of the more recent work atthe Oil Recovery Laboratory. These experiments were conducted to obtainlaboratory data pertaining to the relative merits or efficiencies of variouspressure media in the recovery of oil from a sand reservoir. Two general typesof experiments were conducted. In one the various pressure media were passedthrough an artificial body of sand partly saturated with oil at a constantinput pressure; in the other the pressure media were passed through the body ofsand partly saturated with oil at a constant volume rate. No attempt will bemade to discuss the ramifications of economic problems which enter into thechoice of a pressure medium.

Apparatus and Materials
The two 6-in. by 6-ft. flow tubes described in Technical Publication 144 wereused in these experiments. They consist of 6-ft. sections of 6-in. casing witha blind flange at each end.
Behavior Of Gas Bubbles In Capillary Spaces
Authors: Gardescu Ionel I. 
Published: June 2014

Natural gas influences the movement of oil throughreservoir rock by affecting the physical properties of the oil and the pressurewithin the reservoir. The presence of gas bubbles changes the laws of flow andthe distribution of forces.
The problem of flow of oil and gas through a porousrock is complex, and most authors, in order to analyze their problems, havefound it necessary to make or accept certain generalized assumptions. Some ofthese assumptions, particularly the ones dealing with capillary phenomena andmolecular forces, have not received sufficient attention and by lack ofunderstanding have often been misinterpreted.
Herold has called attention to the resistance offeredby gas bubbles in capillary spaces and has drawn some interesting conclusionswith regard to the action of natural gas in a reservoir rock. He has duplicatedan experiment of the French physicist Jamin, has interpreted his findings interms of molar mechanics, and, from experimental observations, has made anumber of assumptions which he later applies in discussing problems of naturalflow and recovery of oil. The Jamin action is an assumption because it lacks aphysical proof and has never been determined quantitatively.
Tickell attempts to develop a formula expressing thework performed by a distorted bubble. H. A. Wilson, in the recent publicationof the American Petroleum Institute on the function of natural gas, discussesthe phenomenon in terms of classical physics. Both contributions are incompleteand offer no experimental data.
This paper includes a study of the static condition ofequilibrium of gas and liquid bubbles confined to capillary spaces. In order toavoid any possible confusion, it is proposed to restrict the term" Jaminaction"
Drilling Mud Practice in the Ventura Avenue Field
Authors: Hertel F.W. , Edson E.W. 
Published: June 2014

In some fields the problem of mud fluid is simpleand easy of solution. But in the Ventura Avenue field the acquisition anddisposal of good drilling mud is not the least of the problems that confrontthe operator. In fact, mud fluid in the Ventura Avenue field is a veryimportant factor in the drilling of the wells. It is quite probable that manyof the factors affecting mud in this field will not be found in most of thefields with which the reader is familiar. However, in the fields where the mudfluid causes no apparent problem it is probable that some of the points brought out in this paper couldbe used to economic advantage. In fields 'where caving and squeezing formationsand high gas pressures are present, as in the Ventura A venue field, it isbelieved that application of methods outlined will be of great assistance indrilling wells.
On account of the sandy nature of the formation and thelack of suitable shale bodies in the strata drilled through in the Ventura Avenue field, the wells make practically no mud during drilling. It is necessarytherefore to supply drilling mud to the wells that will carry the drill cuttings to the surface, and also will "wall up"the drill hole and prevent the sandy formations from caving.

Mixing And Handling Mud Fluid
The clay used to make the mud fluid is obtained from ashale stratum in the upper Pico (Pliocene) formation found about a mile oneither side of the field.
Since high gas pressures and caving formations werefirst encountered in the Ventura Avenue field and mud fluid was needed tocombat them, the mixing of this mud fluid has gone through a process ofevolution. First, the clay was mined and hauled to the derrick, where it wasshoveled into the well and left for the churning action of the bit to mix intoa mud in the hole. The next move was the construction of a mixer to mix theclay to a mud fluid which was pumped into the well.
Stabilizing Influences
Authors: Oliver Earl 
Published: June 2014

Some two years ago the Petroleum Division of the A.I.M.E. organized aspecial study of unit operation. That method of handling oil pools had beenurged as the remedy that would save the United States petroleum industry fromthe crisis that even then loomed as more than a small cloud on the horizon.Today it is only one of several remedies vigorously advocated.
Proration, regulation of imports, unit operation, constructive marketing andinterstate compacts all have their earnest proponents, but the advocates ofeach have been disposed to look with indifference on the other respectiveproposals, with the result that none has had united support. Meanwhile theindustry has drifted rapidly toward a serious crisis, the imminence of which initself may bring the solution. The gravity of the situation tends to forcestudy of the merits of proposals that a short time previously were brushedaside as impractical; and to the surprise of most of us we now find merit wherepreviously we thought none existed.
Irrespective of what might have been the result had any single proposal beingadopted years ago, it is now apparent that under present conditions no one ofthe remedies-unit operation, proration, regulation of imports or constructivemarketing-standing alone would be of much benefit. On the other hand, it isbecoming evident that a well balanced program comprising all four of theseremedies might save the United States petroleum industry; also that some suchcomprehensive program might be necessary to save it.
It is even becoming evident that the despised interstate compact might be anappropriate type of machinery in which to group and coordinate all theseremedies. We have progressed beyond the belief that either the industry or thegovernment working alone can correct the situation, and have arrived at themore healthy realization that the task will require most sympatheticcooperation between government and industry, backed by an equally sympatheticpublic understanding.
Control of California Oil Curtailment
Authors: Allen Robert E. 
Published: June 2014

The organized curtailment of California oil production is not yet one yearold but during its first year it has accomplished so much that it is now firmlyestablished as an agency of economic efficiency. The principle of cooperativecurtailment has been adopted by other states and it is safe to say that theprinciple will continue as long as the demand for petroleum is notably lessthan the potential production. It is interesting to note that this sameprinciple of regulating supply to meet demand is now being urged for otherindustries, such as agriculture and mining.
Since Oct. 31, 1929, when curtailment was instituted by the oil producers ofSanta Fe Springs and Long Beach in an effort to avert the disaster of ruinouslylow prices which confronted them, there has been a constant and increasingly effective curtailment program in California. Prior to that time a notableeffort toward the restriction of oil production was made under the direction ofF. C. Van Deinse during the early summer months of 1929. A considerablereduction of oil output was recorded as the result of this effort, but becauseof incomplete cooperation and the discovery of still deeper zones at Santa FeSprings the effort was abandoned; flush field production became unrestrainedand prices soon fell to low levels.
This initial curtailment movement was educational and experimental.
It showed all operators a way out of their overproduction difficulties anddeveloped the principles followed in later curtailment efforts. Thus it wasthat only a few days after their oil had been reduced to 60 c. per barrel, theoperators of Santa Fe Springs got together and agreed to restrict their currentproduction of more than 270,000 bbl. daily to not more than 150,000 bbl. daily.The operators at Long Beach followed the same course a few days later andagreed to limit their production to not more than 110,000 bbl. daily.
The Santa Fe Springs operators chose H. P. Grimm as umpire and director oftheir proration program. Neal H. Anderson was chosen umpire for Long Beach.Since that time, as the need for curtailment has increased, practically everyfield of the state has come under the curtailment of these two umpires.
Proration of Yates Pool, Pecos County, Texas
Authors: Hardison H.C. 
Published: June 2014

The Yates pool, Pecos County, Texas, has greater potential capacities thanany other field in the United States. This field is notable for the largereturn it yields on capital invested, for low production costs and for theorderly and conservative manner in which it was developed and continues to beoperated.
The proven area is 20,000 acres and there are 392 producing wells, orapproximately 1 well to 50 acres. The theoretical daily potential is 5,250,000bbl. as determined by I-hr. open-flow gages. Individual well gages vary from afew barrels to 8500 bbl. per hour, and well depths range from 1000 to 1800 ft.The greater part of the production is from a very porous limestone, and byagreement no productive well has penetrated the lime more than 225 ft. Theforces driving the oil from the formation to the surface are hydrostatic head, expanding gas or a combination of the two. The degree of effectiveness ofeither depends upon the structural position of, and porosity encountered in, the individual wells. Approximately 95 per cent. of the wells in the field flownaturally. The pipe line outlet of the field at the present time is 100,000bbl. per day, which is less than 2 per cent. of the daily potential.

Difficulties And Principles Of Proration
It became evident during the first year of the development of this field thatoperators would have to devise a scheme to allocate pipe line runs equitablyamong their different properties. When the idea of proration was firstinaugurated, the matter of spacing wells was given consideration. This wasgiven up through fear of legal difficulties. Storage was also a question thatwas given considerable thought, and a plan was finally developed which wentinto effect Oct. 1, 1927. It was decided that the oil runs should be proratedaccording to the total potential capacity of all the wells which the severaloperators had in the field. The potential capacity of the wells was measured bya 1-hr. openflow gage. All runs to storage by an operator were deducted fromhis daily allowance.
Development in a Part of the Ventura Avenue Oil Field
Authors: Jensen Joseph , Hertel F.W. 
Published: June 2014

Many fields have been zoned by nature with shales and intermediate watersbetween oil zones. Limitations thus imposed have been the basis on which afield was developed. In contrast thereto, in the Ventura Avenue field, natureproved more generous. Always expecting to find such similar limitations, operators drilled deeper and deeper into the oil zone without finding anydistinctive shale bodies other than the Gosnell shale and only one intermediatewater, which became the point below which the final water shut-off of each wellwas made. Thus, on top of the structure, about 3300 ft. of oil-bearing zone hasbeen penetrated below this intermediate water--a distance of 4000 ft. below theGosnell shale. At first it seemed that the greater penetration in the zone, thebetter the well. The error of this assumption became evident as time passed.Other pressing attendant problems requiring consideration also developed.
In the spring of 1929, the Associated Oil Co., still having a large undrilledarea, adopted a method for developing this land by dividing the oil formationinto zones, so as to drill two classes of wells and to prepare for others, ifconditions in the future justified or required such action. Wells now completedare considered as permanent completions in the zone or class for which they aredrilled, and are not looked on as a ready means for deepening or accepted as atemptation for deepening to get some flush production quickly. Provision hasalso been made to avoid future water problems.
The most striking demonstration resulting from such work is the fact that thetop of the structure is far from being the point at which the largest oilrecovery is made. Wells on the flank of the structure invariably produce withlower gas-oil ratios and secure much larger oil production.

Zoning Of Oil Sands
The Gosnell shale separates the upper light 50 gravity oil from the lower 30gravity oil below. As the light oil zone is of practically no importance atpresent, it is not being exploited.
Bottom-hole Pressures in Oil Wells
Authors: Millikan C.V. , Sidwell V. 
Published: June 2014

There is nothing more important in petroleum engineering than a definiteknowledge of the pressure at the bottom of an oil well at any existingoperating condition, and the relation of this pressure to the pressure withinthe producing formation. A knowledge of bottom-hole pressures is fundamental indetermining the most efficient methods of recovery and the most efficientlifting procedure, yet there is less information about these pressures thanabout any other part of the general problem of producing oil.

Determination Of Bottom-Hole Pressures
Bottom-hole pressure may be calculated or determined by several methods. On aninactive well it may be calculated from the fluid head or, if the well is shutin, by adding the casinghead pressure, the static head of the gas and the fluidhead. In wells flowing naturally through tubing the pressure at the bottom ofthe tubing may be calculated by adding the pressure at the casinghead betweenthe tubing and the casing and the pressure due to the weight of the column ofgas, but there is always possibility of error caused by fluid being in theannular space above the bottom of the tubing. If a well with tubing is flowingthrough either the annular space or the tubing, sufficient gas may be injectedthrough the static space to insure that it is free of fluid but not sufficientto establish an appreciable friction loss. The pressure at the bottom of thetubing can then be calculated by adding to the pressure at the tubing head thepressure due to the weight of the column of gas. This is probably the mostaccurate method of calculating bottom-hole pressures. In wells flowing bygas-lift, the pressure at the point the gas enters the flow may be calculatedby a gas-flow formula.
Several types of pressure bombs have been used to measure the pressure at thebottom of wells. One is a piece of steel tubing with a check valve in thebottom and a connection for a pressure gage at the top.