A Primer Of Oilwell Drilling (5th edition)

1、DRAKES WELL AND SPINDLETOP? Introduction: Drakes Well and Spindletopn the ?s, unlike today, drillers took Sundays off, but oneISunday afternoon in August ?, William Smith decided toinspect a well he was drilling. Perhaps Smith, known as UncleBilly to his friends, was curious to see if anything had h

2、appenedwhile he was in church. The well, near Oil Creek just outsideTitusville, Pennsylvania, sat next to an oil seep, a place where oilfrom subterranean rocks oozed to the surface.Uncle Billy had begun drilling the well in April for a formerrailroad conductor named Edwin Drake. Drake, whom every-on

3、e called “Colonel, was overseeing a remarkable project: hewas supervising the drilling of a well whose sole purpose wasto produce oil. Asians and Europeans had drilled oilwells, butno one in the United States had. Some of the local residentshad also drilled wells near Titusville before ?. These well

4、s,however, were saltwater wells.Uncle Billys visit to the well that particular Sunday turnedout to be fruitful. He peered into the pipe that encased the topof the hole and saw that it was full of crude oil. When wordspread, dozens of new rigs appeared in the area and the boomwas on. This small proje

5、ct in Titusville marked the beginningof the petroleum era in the United States.THE SETTINGTwo circumstances had inspired Colonel Drake and hisbackersa group of New Haven, Connecticut, bankerstodrill for oil. One was a shortage of whale oil; the other was theinability of earthen dams at Oil Creek to

6、retain oil that seepednaturally from the earth.By the ?s, New England seafarers had hunted whalesnearly to extinction. Because people used whale oil as a high-quality lubricant and as an illuminating oil, it was scarce andexpensive. Reports of an oil spring near a Pennsylvania creek,where the oil li

7、terally leaked out of the rocks, therefore sparkedthe interest of the New Haven entrepreneurs. They reasonedthat if they could recover enough rock oil from the Oil Creeksite, they could sell it as an inexpensive substitute for whale oil.They formed the Pennsylvania Rock Oil Company of Con-necticut i

8、n ? and began thinking of ways to extract the oil.?A PRIMER OF OILWELL DRILLINGSince the oil seeped onto the ground near the creek, it had tobe contained. First, the bankers hired workers to dig trenchesand direct the oil into holding ponds. To make the ponds, thelaborers simply dug out the soil and

9、 piled it around the edgesof the pond. Unfortunately, every time they built such a wall,rainwater and groundwater washed it out and the oil ran offinto the creek.To solve the problem, James Townsend, president of thenewly formed oil company, proposed drilling for the oil,rather than merely trying to

10、 contain what seeped to thesurface. Others in the area had been drilling for salt water, orbrine, for many years. Townsend hired Drake, declared himan honorary colonel, and sent him to Oil Creek to supervisethe drilling for oil. Drake, in turn, hired Uncle Billy Smith, anexperienced saltwater drille

11、r.THE PROBLEMAlmost two years passed, however, before Colonel Drake andUncle Billy began drilling. Technical problems plagued themfrom the start. The worst problem concerned the way peopledrilled brine wells. Workers customarily dug out the topsoil atthe well site until they reached bedrock. Then th

12、ey built adrilling rig over the hand-dug opening, or cellar. Using the rig,they drilled a hole into the exposed bedrock. Since the bedrockwas hard, it did not cave in. Further, with all the loose topsoilremoved, nothing impeded the brines flow from the open, orunlined, hole in the bedrock.THE SOLUTI

13、ONAt Oil Creek, it was another story. Groundwater kept filling upand caving in the cellar long before the excavators reachedbedrock. As a result, they could not remove all the loose soilfrom the cellar. The loose dirt and water clogged any holedrilled into the bedrock. Fortunately, Drake solved the

14、prob-lem. He and Uncle Billy drove steel pipe into the soft grounduntil it reached bedrock. Once this pipe, or casing, was seatedon the bedrock, it prevented the topsoil from caving in. Thenthe drillers built the rig, ran the drilling tools inside the casing,and drilled the rock.In spite of Drakes g

15、etting the well started, many thought theproject was a waste of time and money. In fact, they referredto it as Drakes Folly. A serious setback came when stock-holders in the Pennsylvania Rock Oil Company refused tosink any more money into the venture. Soon, even Townsendlost faith. By August of ?, h

16、e had decided to call it quits.DRAKES WELL AND SPINDLETOP?Figure 1.The Drake wellAs the story goes, he sent a letter from New Haven instruct-ing Drake to abandon the well. Meanwhile, in Titusville,Uncle Billy and Colonel Drake continued to drill because theydid not know about Townsends letter. Legen

17、d has it that itwas only a few days before the letters arrival that Uncle Billydiscovered that the well was a success.Figure 2.Drilling the deepest well inTHEN AND NOWthe United StatesDrilling operations have changed greatly since Drakes well(fig. ?). It reached a total depth of about ? feet (about

18、?metres), not very deep even for ?. Indeed, Colonel Drakebragged that he could drill as deeply as ?,? feet, or over ?metres, if necessary. In ?, after ? days of drilling, LofflandBrothers Rig ? bottomed out a hole at ?,? feet, or ?,?metres (fig. ?). The well, now plugged and abandoned, was insouthwe

19、stern Oklahoma and it is still a record depth for theUnited States.In the late ?s, the former Soviet Union drilled a well tomore than ?,? feet, or ?,? metres. It is in Russia on theKola Peninsula, east of Finland. Scientists and engineersplanned it to reach about ?,? feet, or ?,? metres, whichis ove

20、r ? miles (? kilometres) deep. Work on the well ceasedin ?, when it reached ?,? feet (?,? metres). Inter-estingly, neither the drillers in Oklahoma nor those on theKola Peninsula struck petroleum. So Drakes little ? footerstill has a leg up on the two deep wells.?A PRIMER OF OILWELL DRILLINGSPINDLET

21、OPLets go back in time againthis time to Texas. It is January ?,?. Anthony Lucas, an Austrian-born mining engineer, issupervising the drilling of an oilwell. His drilling crew has justinstalled a new drilling bit on the string of drill pipe. Theyvebeen at the drill siteSpindletop, a small knoll just

22、 south ofBeaumontsince October ?, ?.The drilling crew begins lowering the new bit to the bottomof the hole. They run about ? feet (? metres) of drill pipeinto the ?,?-foot (?-metre) hole. Suddenly, the well startsspewing drilling mud. The mud, a liquid concoction thatcarries rock cuttings out of the

23、 hole, drenches the rig floor andshoots up into the derrick.The crew evacuates the rig and waits to see what will happen.The flow stops. The workers return to the rig and start cleaningup. Without warning, mud erupts again. Then a geyser of oilgushes ? feet (? metres) above the ?-foot-high (?-metre-

24、high) derrick (fig. ?). The spouting oil blows all the drill pipeout of the hole. The blowing well elates Lucas and his crew asthey watch the display from a safe distance. They estimate thatit is flowing over ? million gallons (over ?,? cubic metres)of oil per day. In oilfield terms, thats over ?,?

25、barrels of oilper day.Before Spindletop, a big producer flowed ? barrels (? cubicmetres) per day. The Lucas well produced ?,? times thatamount. It showed that buried layers of rock could containtremendous amounts of oil. What is more, it proved thatFigure 3.The Lucas wellrotary drilling was an effec

26、tive way to obtain it. Spindletopmarked the beginning of the modern petroleum industry.CABLE-TOOL VERSUS ROTARY DRILLING? Cable-Tool Versus Rotary Drillingf you dont count picks and shovels, two drilling techniquesIhave been available since people first began making holes inthe ground: cable-tool dr

27、illing and rotary drilling. Both methodsoriginated a very long time ago. Over ?,? years ago, for in-stance, the Chinese drilled wells with primitive yet efficient cable-tool rigs. (They were still using similar rigs as late as the ?s.) Toquarry rocks for the pyramids, the ancient Egyptians drilled h

28、olesusing hand-powered rotating bits. They drilled several holes in aline and stuck dry wooden pegs in the holes. They then saturatedthe pegs with water. The swelling wood split the stone along theline made by the holes.?A PRIMER OF OILWELL DRILLINGCABLE-TOOL DRILLINGColonel Drake used a cable-tool

29、rig to drill at the Oil Creeksite. Such rigs feature a cable to which workers attach a sharplypointed bit. Workers also attach heavy weights called jarsabove the bit. Rig machinery lifts the cable, the bit, and theweights, and then drops them. The falling bit strikes theground with a heavy blow. It

30、punches its way into the rock(fig. ?). Repeated lifting and dropping makes the bit drill.Cable-tool drilling is very efficient in hard-rock formationssuch as those Drake, Smith, and others drilled in Pennsylvania.From time to time, however, workers have to stop drilling,pull the bit from the hole, a

31、nd remove the pieces of rock, orcuttings, the bit makes. If the crew fails to bail out the cuttings,the cuttings will obstruct the bits progress. What is more,cable-tool drilling is not suitable for soft-rock formations, assoft-rock fragments tend to close around the bit and wedge itCASINGin the hol

32、e. The rock formations over the oil reservoir atSpindletop were so soft they stuck the cable-tool bit. Lucastherefore had to drill with a rotary rig.ROTARY DRILLINGA rotary drilling rig turns, or rotates, the bit on bottom to drill,CABLEor make hole (fig. ?). Crew members attach the bit to the endof

33、 a length of pipe. By adding more pipe, they lower the bit tothe bottom of the hole. With the bit on bottom, the drillerstarts rotating it. Some of the weight of the pipe is allowed toHEAVYpress down on the bit. The weight causes the bits cutters to WEIGHTS (Jars)bite into the formation rock. Instea

34、d of being a chisel, a rotarybit has several rows of metal teeth or diamond cutters (fig. ?).As the bits teeth or cutters rotate over the formation, theyBITgouge or scrape the rock away.Figure 4.Cable-tool drilling rigCABLE-TOOL VERSUS ROTARY DRILLING?Figure 5. An early (about 1916) rotary drilling

35、rig; therotary machine is in the foreground to the right.Figure 6.The cutters onthis bit are steel teeth.?A PRIMER OF OILWELL DRILLINGFluid CirculationBy itself, rotating a bit on pipe is not any better than droppinga bit on cable. A special feature, however, gives rotary drillinga major advantage r

36、egardless of whether the rock is soft, hard,or anywhere in between. A rotary rig circulates fluid while thebit drills. Crew members attach a rotary bit to hollow pipe,instead of to braided cable. The pipe becomes a conduit: apowerful pump can move fluid down the pipe to the bit andback to the surfac

37、e.The fluid is usually a special liquid called drilling mud. Themud shoots out of the bit and picks up the cuttings. The mudthen carries the cuttings up the hole to the surface. At thesurface, equipment removes the cuttings. The pump recircu-lates the clean mud back down the pipe. Mud circulatescons

38、tantly to remove cuttings while the bit drills (fig. ?).Thus, on a rotary rig, workers do not have to stop drilling tobail cuttings. Even more important, they usually do not haveto worry about soft-rock formations caving in on the bit andsticking it. The circulating mud moves the cuttings away fromt

39、he bit and stabilizes the hole. The advantage of being able tocirculate drilling fluid has all but made cable-tool drillingdisappear. Even though companies may use a cable-tool rig ina few special cases, more often they use rotary rigs.PUMPDRILLPIPEFigure 7. A pump circulatesBITdrilling mud down the

40、 drill pipe,out the bit, and up the hole.COMPANIES AND PEOPLE? Companies and Peoplerilling a well is a complicated job. It is so complex, in fact,Dthat no single company is diverse enough to perform allthe required work. Instead, many companies and individualsare involved. The companies include oper

41、ating companies,drilling contractors, and service and supply companies.OPERATING COMPANIESAn operating company, or an operator, obtains the right to drilland produce petroleum at a particular site. The operator buysor leases that right from the owner of the rights to the subter-ranean oil or gas. Ri

42、ghts can be owned by individuals, compa-nies, or, in some cases, by the federal or state government.An operator can be a major, such as Exxon, Mobil, BritishPetroleum, Shell, Chevron, or Texaco. A major oil companyproduces oil and gas and transports them from the field to therefinery and plant. It a

43、lso refines or processes the oil and gasand sells the products to consumers.An operator can also be an independent. An independentoperator is an individual or a relatively small company thatproduces and sells oil and gas but does not transport, refine, ormarket them. Operating companies, whether maj

44、or or inde-pendent, pay for the drilling of a well. They usually hire adrilling contractor to drill it.?A PRIMER OF OILWELL DRILLINGDRILLING CONTRACTORSIn the United States and Canada, drilling contractors dovirtually all the drilling. Operators have found it more cost-effective to hire a firm that

45、specializes in drilling than tomaintain their own rigs. A drilling company may be small orlarge; it may drill mainly in one country or it may have rigsworking all over the world.In any case, a drilling companys job is to drill a hole. It mustdrill the hole to the depth and specifications set by the

46、operat-ing company. An operating company usually invites severalcontractors to bid on a job. Often, the operator awards thecontract to the lowest bidder, but not always. Sometimes agood work record may override a lower bid.SERVICE AND SUPPLY COMPANIESThe drilling of any well involves several service

47、 and supplycompanies. Supply companies sell expendable equipmentand material, such as drilling bits and mud, to the operatorand the drilling contractor. They also sell items such as drillpipe, fuel, lubricants, fire extinguishers, and spare parts. More-over, they market safety equipment, rig compone

48、nts, paper,water, tools, computers, paint, grease, rags, and solvents.Think of any part or commodity that a rig needs to drill a well,and youll find a supply company on hand to fill it.Service companies offer special support to the drilling op-eration. Like supply companies, they exist to fill the s

49、pecialneeds of the drilling project. For example, a mud loggingcompany logs, or monitors, the drilling mud as it returns fromthe well. The returning mud carries cuttings and any forma-tion fluids, such as gas or oil, to the surface. The operator cangain much knowledge about the formations being dril

50、led byanalyzing the returning drilling fluid.Another kind of service company provides casing crews.A casing crew runs large pipe into the well to line, or case, it(fig. 8). Casing protects formations from contamination andstabilizes the well. After the casing crew runs the casing,another service com

51、panya cementing companycementsthe casing in the well. Cement bonds the casing to the hole.In many cases, when a well reaches a formation of interest(usually, a formation that may contain oil or gas), the operatorhires a well logging company. The well logging crew runssophisticated tools into the hol

52、e. These instruments measureand record formation properties. By looking at the record, orFigure 8. A casing crew memberwell log, the operator can often determine whether the well willhandles a length of duce oil or gas.COMPANIES AND PEOPLE?PEOPLEWhile it is true that you cant drill a well without a

53、drilling rigand several companies to back up the rig, it is equally true thatyou cant drill a well without skilled people. Personnel run therig and keep it running until the well reaches its objective. Letslook at some of the people involved in drilling.Drilling CrewsDrilling crews work for the dril

54、ling contractor. Typically, thecontractor hires a rig manager, or a superintendent, for eachrig. This rig manager is usually called the toolpusher. The tool-pusher supervises two or three crews that operate the rig ?hours a day, ? days a week.Besides the toolpusher, each rig has drillers, derrickhan

55、ds,and rotary helpers (also called floorhands or roughnecks).Sometimes the driller designates the most experienced rotaryhelper as a motorhand. The motorhand performs routineservice and maintenance on the rigs engines.ToolpusherThe toolpusher is the contractors top hand on the drillinglocation. This

56、 person oversees the drilling crews that work onthe rig floor, supervises all drilling operations, and coor-Figure 9.A driller at his position on thedinates operating company and contractor affairs. During therig floortime the rig is drilling, the toolpusher usually lives in an on-sitetrailer or por

57、table building and is on call at all times.DrillerThe driller supervises the derrickhand and the rotary helperswith direction from the toolpusher. From a control console onthe rig floor, the driller manipulates the controls that keep thedrilling operation under way (fig. ?). This person is directlyr

58、esponsible for the drilling of the hole.?A PRIMER OF OILWELL DRILLINGDerrickhandWhen crew members run drill pipe into the hole (trip in), orwhen they pull pipe out of the hole (trip out), the rig needs aderrickhand. (A derrickhand is often called a derrickman, butderrickhand is becoming a popular te

59、rm. This book uses theless sexist term.) The derrickhand handles the upper end of thepipe from the monkeyboard (fig. ?). The monkeyboard is asmall platform in the derrick. A drilling crew can trip pipe inor out of the hole one length, or joint, at a time. Usually,however, they trip pipe in stands to

60、 speed up the process. Sincea stand is two or more lengths of pipe, the job goes faster thantripping them one joint at a time. Each stand of pipe is eitherabout ? feet long or about ? feet long (about ? or ? metres).The contractor therefore mounts the monkeyboard in thederrick at a height of either