The Kilgore News Herald from Kilgore, Texas • 47

r'i wfyrc rrr rrx: "t-tt- wrr9r 9 Sunday July 2 1978 KILGORE NEWS HERALD Page 11C Born-Again Oil Fields More Oil Now Being Coaxed From Established Fields By JIM MAYES In The Amoco Torch Remember the old story about the back-country farmer who had no use for the county A 9 A 1 vl AA Waa a 1 I aocnt'a nHvW Wo i a increasing amounts of water with the oil As I recall the second well we drilled was for saltwater disposal "WE GOT to wondering why produced or from other sources to maintain or enhance the strong water drive that naturally Johnson says In several Gulf coast and says in several uuu coasi ana tine re be wasn a the wells behaved the way they East Texas fields possessing pi dld- dld logging and active a i barrel good as he knew Well many years and today its production operations there are overseen from area offices located in Andrews Brownfield (Slaughter area) Levelland and Odessa With a production rate of 41000 barrels of oil per day the Andrews area ranks fourth among Houston division field locations The area office oversees about 30 company-operated waterfloods most of which are unitized that is operated jointly for the benefit of Amoco other working-interest owners and royalty owners Amoco is moving toward the initiation of several enhanced-recovery projects and already has three pilots underway Jim Collier area engineer in Andrews believes that a substantial number of that present secondary recovery units eventually will DAVID ELLISON DAN GOODWIN and Mrs Harold Dial pianist officers also assumed their leader Rotary SERVICE CLUB PRESIDENTS Among Kilgore service clubs are Kilgore Lions Club Kilgore Rotary Chib and Kiwanis Club of Kilgore Officers of the Lions Club assuming their duties July 1 include David Ellison president Bobby Bittick first vice be subjected to EOR president Hancock second vicq Meanwhile several of the president Rudy Manos third vice president Rex Whitten and James Padgett second-year directors Light and Harry Douglas first-year directors Hyman Laufer secretary-treasurer John Latham Lion tamer Bud Beaty tail twister Taylor camp chairman Harold Dial song current projects infill drilling central tank batteries and downhole (submersible) pumps are consistent with eventual EOR while at the same time improving present recovery rates "SO MUCH of what we are able to do depends on the price duties on July 1 Included are Dan Goodwin president Dickerson vice president Stem-bridge secretary-treasurer and Tom Morris Kit Murphy and Charles Florio directors The current Kiwanis slate took office last October Included are Anderson Ill president Jerdy Wolverton vice president Bill Black secretary Mike Bassham treasurer Pete Rodriguez past president and Roger Terk and Gene Turner surface locations A few years agok oil prices have enabled Amoco drillers to test the theories developed tjy Etheredge now with "new rices of about $12 per allowed by the federal government the field is being "re-evaluated with the even though most of its tiny reservoirs are expected to yield no more than 30000 barrels of oiL Unlike most East Texas and Gulf coast fields where oil-producing coast fields where oil-producing mechanisms are associated with major waterbearing zones typical West Texas fields have reservoirs that engineers refer to as exhibiting volumetric depletion In terms this means that every time a barrel of oil or water is produced a void is created in the reservoir pore space Over a period of time this lessens downhole pressure and makes it increasingly difficult for oil to move to the wellbore In the early days of oilfield development the only response to declining reservoir pressure was the installation of surface pumps followed by abandonment whpn wells became uneconomical to produce MORE recently of course water-flooding has permitted the recovery of additional amounts of oil and more recently still engineers have sought to forestall pressure drops by initiating water-flooding and gas injection procedures early in the life of the field In future years as technology is perfected and oil prices permit enhanced oil recovery (EOR) techniques such as miscible-phase displacement and carbon-dioxide injection can hopefully commence even before fields reach maturity presence in the Permian Basin extends back mechanisms Amoco expects to recover as much as 50 to 70 percent of the original oil in place SOME 150 miles up the Texas coastline lies another small field where increased activity has teen made possible through the courtesy of improved economics Unlike the sweeping expanses of open country that usually characterize oilfield development South Houston field underlies a heavily populated area of modest homes and small businesses The entire field will) an areal extent of about 400 acres is only nine miles from the heart of Houston Although Amoco has known of South existence for many years (the field was discovered in 1935) only recently has the company started to unravel the complex nature of its numerous fault-block reservoirs But even after the Houston Morris Etheredge began unlocking the salt long-hidden secrets the problem of reaching reservoirs uner homes and businesses remained to be solved THE ANSWER was directional drilling from a centrally located 18-acre drillsite In this way the company has managed to reach a number of separate reservoirs some located as far as 1200 horizontal feet from the drillsite This difficult and expensive method has teen pioneered from platforms on offshore locations but it is still relatively new to on-shore sites where most reservoirs can be developed by drilling vertical holes from conventional at which the government will allow us to sell our Collier explains three different price tiers and constantly changing base levels we find that we must evaluate every project not only in terms of its engineering feasibility and potential for yielding additional quantities of oil but also in terms of what the government will allow us to sell it Despite the delicate and often precarious pricing abnormalities introduced by government edict the company is investing heavily in Permian Basin production facilities Pulling a heavy binder at random from a file drawer Collier cites the Breedlove-Devonian field in Martin county as a representative example of what is being done "LAST he says completed installing high-volume submersible pumps on all the wells and completed fieldwide electrification We also expanded facilities at our central tank battery to handle higher water volumes and this enabled us to shut down some old lease batteries The high-volume pumps have created some casing problems caused by higher pressures and so been doing some remedial workovers In total spent about $12 million and increased our initial oil-production rate from 1050 barrels daily to 2800 barrels per day Water production also has increased to about three times its initial So it goes throughout the state and indeed throughout the nation: Everywhere the company operates new work is being done new technologies applied and new men and women employed to add their expertise to the challenge of producing more oil and natural gas Higher prices not only are enabling Amoco to get more oil and gas from existing reservoirs they also are encouraging the company to seek new and tetter means of conserving energy in all its field operations EXAMPLES of conservation practices abound: Gas once was used almost exclusively to fire heater-treaters that separate produced water from the oil Now gas is giving way to cold treatments involving emulsion-breaking chemicals and longer residence times Oilfield electrification not only is allowing companies such as Amoco to bring more produced oil and gas to market but also is powering automated controls that improve operating efficiency Moreover Texas utilities once dependent on natural gas for electric-power generation are turning increasingly to more plentiful coal and lignite East ji down in the Lone Star State these days oilmen are as good as they know how By applying sometimes esoteric ana always high-cost technology to oil and gas fields discovered in prior years they are reaping second and even third crops from reservoirs that likely would have been abandoned as recently as a decade ago Jerry Brown engineering manager for Amoco Production Houston division says "more than ever before getting the last drop of oil and cubic foot of gas out of our existing reservoirs Amoco has always had that as an operating philosophy but new technological advances and an Improved economic climate have provided the incentive to take new looks at the investment qpportunities in existing fields And although we have always tried to operate our fields as efficiently as possible higher prices -particularly for natural gas -have encouraged renewed efforts in the area of energy THE ANALOGY between farming and petroleum development is limited of course by the finite nature of oil and natural gas Like land just not making petroleum anymore Still estimates by the US Geological Survey indicate that some 50 to 60 billion barrels of Oil and at least 300 trillion cubic feet of natural gas remain to be recovered from existing US oil fields Because Texas alone is thought to possess nearly half of the recoverable reserves in the lower 48 states a target well worth shooting at And Houston division -with responsibility for all our Texas production except that of the upper Panhandle has its fowling pieces primed loaded and cocked The inital salvos in fact already have been fired BROWN says that no stone is being left unturned no technology overlooked in quest for maximum oil and gas recovery "Especially for the young engineer or earth scientist eager to apply his or her professional skills these have got to be exciting he adds Bob Johnson assistant nods agreement then ticks off an impressive list of fields in which high-volume lift equipment is being installed tight sands routinely fractured well spacing densified waterhandling facilities constructed directional drilling implemented and conservation measures initiated you want to Johnson explains "is that no two oilfields are exactly alike when it comes to reservoir mechanics What works in one might not work at all in another This means that we devote a great deal of time and effort and eventually money to engineering the best approach Generally speaking Gulf coast fields possess natural water drives that are virtually self-perpetuating so primary recovery extends over a period of many years A number of West Texas fields on the other hand have reservoirs in which waterflooding must be initiated at an early stage followed ultimately by enhanced oil-recovery methods at an optimum point in their development to attain maximum yield important point to keep ip mind both from the standpoint of engineering concepts and from the investment view is that none of the methods being employed is mutually exclusive The installation of high-volume lifting equipment for example usually requires central tank battenes to handle much larger volumes of water which in turn require Injection pumps disposal wells and additional pipelines to carry produced water from tank battery to disposal wells Frequently too the installation of high-voiume lift equipment will be accompanied by an Infill drilling program to increase well density or to provide spacing patterns best suited to the reservoir hydraulics of a particular field" ABOUT midway between the historic Gulf coast cities of Victoria and Corpus Christi is a small oilfield that symbolizes the determination to maximize petroleum recovery Known as the Live Oak Lake field (after a body of water that it surrounds) the field is presided over by area foreman Joe Russell and his field foreman Doug Sanford They are veterans who know the oil business inside out "When Amoco discovered this field back in Russell drawls "we think we had much We developed the main portion of the field on a 40-acre spacing pattern and the typical well made about 100 barrels of oil a day Although the pro-( duction rate held fairly well the wells soon began to produce found Uial tlie high vertical permeability incurred early coning of the In ordinary language this simply means that formation water would rather flow up than sideways and so migrates rapidly into the oil-bearing part of the formation as oil is produced Partially because of its high water-oil ratio and some other undesirable characteristics the Live Oak Lake field has been developed in several stages These have included the initial drilling program from 1965 to early 1968 that resulted in 37 oilwells two additional wells along the flanks late in 1968 and four infill wells in 1974 Beginning early in 1976 a 14-well program waf begun to bring the west-central portion of the field to 20-acre spacing All told about 70 wells have been drilled and 34 of these are currently producing A RECITATION of the development rolls off Joe tongue like a black-eyed pea off a knife blade He was sent to the field from Hastings to oversee drilling of the first well And he has teen keeping an eye on the field ever since In 1968 Russell was replaced as field foreman by Sanford and transferred to Corpus Christi area office He has headquartered there as area foreman since that time riding herd on a score of fields in the north end You get the feeling though that Live Oak Lake remains his abiding interest tell you how many times the company has been tempted to walk away and leave that little Joe says about it says and heaven knows had our problems The volume of water to be lifted makes standard pumping units uneconomical sand problems prohibit the use of submersible and electrification been readily Despite the problems Amoco has persevered and continued to develop the field Today its wells produge some 1400 barrels of oil and 40000 barrels of water a day All the oil is produced by gas lift a high-volume method that involves pushing compressed gas down the annular space (between tubing and casing) Oil water and the introduced gas are forced back up the tubing roughly comparable to shaking up a bottle of soda pop holding your thumb over the mouth and letting it spew The gas-lift method used at Liye Oak is shown as rotated system This means the gas which expends much of its pressure in lifting produced fluids is separated out of the oil and water at a central tank battery (CTB) piped to enormous compressors where it is repressured and then reinjected all over again says Russell "the volume of new gas involved is relatively small and practically none of it is THE HEART of the Live Oak Lake operation is its central tank battery a collection of tanks pipes pumps compressors meters valves and specially designed treating and separating vessels that take on the appearance of a miniature refinery All told therv CTB at Live Oak Lake represents an investment of $3 million (Other CTBs especially if they involve the extraction of light hydrocarbons from casing-head gas can run higher) Following residence time and chemical treatment to separate it from produced water and sediment oil from the CTB is metered through automatic custody transfer (ACT) units to a transmission pipeline that starts it on its way to the refinery The produced water after being stripped in three stages of its oil content and chemically treated to inhibit scale and corrosion (that could plug injection wells) is piped off to disposal wells A FORTUITOUS turn of nature allows the million-plus barrels of brackish formation water produced each month by Live Oak Lake wells to be readily injected into a shallow (3200 feet) formation known locally as the Greta sand Because of this extremely high porosity and permeability only five disposal wells are required and injection pressures need not exceed 400 psi The Greta sand is oil-productive in other nearby fields but here it is a vast salt-water aquifier Bob Johnson explains that in many of the state's oilfields produced water is re-injected into the same formation from which it was produced Live Oak Lake produces from the Frio sand an Oligocene age formation encountered in this area at about 6000 feet Typical of several Gulf coast sands the Frio at Live Oak Lake produces through the mechanism of an active water drive that perpetually renews itself "This means that there is no need to re-inject water either 'he IBoorn We're proud fo be a now port of this community ond to join our name with the great Oldsmobile and Cadillac name We look forward to serving all of you who own or will own one of America's great luxury cars Oldsmobile and Cadillac You're Invited to visit our showroom To meet our sales personnel ond service staff And to test drive the new breed of Oldsmobile and Cadillac John Harris Harris Oldsmobile-(Cadillac Co 1604 Huy 259 North Kilgore 4.