COMMENTARY Quenching the wild wells of Kuwait Richard L. Garwin and Henry W. Kendall The last of the hundreds of oil-well fires left in Kuwait by Iraq should be capped this week. Although progress has been remarkable, a mechanism is needed to cope with future large-scale disasters. BEFORE the liberation of Kuwait by US control teams. Moreover, innovative efficiency of the capping-in effort so far. forces and their coalition partners, the techniques were thought to be required By early October, more than 550 wells government of Iraq detailed about 1,000 to deal with large numbers of mines in had been brought under control, with military explosive experts and 3G-40 en­ non-combat circumstances. There was remaining 140 expected to be capped by gineers, together with the enforced initial concern, later shown to be the end of this week. Nearly 30 crew assistance of people who worked in the groundless, that wells would be booby­ were used. oil fields, to sabotage and set fire to the trapped. Mine fields were later found to It is evident that we are not the most 1,000 or so oil wells of Kuwait. Thirty to have been laid outside, but not within, knowledgeable people about well con­ forty pounds of the military explosive C4 the oil fields. trol, but we write to provide some re­ were used with sandbag tamping. Sabot­ We, together with Howard Ris and levant information, and to indicate how age attempts were made on 732 wells the Union of Concerned Scientists, orga­ people could contribute to the solution and were successful in damaging and nised a symposium (later called Desert of such problems and similar ones that starting oil flows in 690 of them, about Quench) in Washington, DC, on 2-3 640 of which were also set on fire. Data April this year, to bring together scien­ The classical approach are scarce, but it seems that something tists and experts in wells and well control The classical and well-practiced control near 2-3 million barrels per day were - including several people from the of a wild well involves delivering cubic being lost initially, considerably less than Kuwait Petroleum Company - to metres of water per minute to the equip­ the 6 million barrels per day estimated address these problems, discuss the usual ment involved close to the fire, to keep by Kuwaiti authorities, yet still repre­ solutions, and to search for means to it at operating temperature at a distance senting a loss of as much as US$50 expedite control of the wells and deal at which it would normally melt, and to million per day. with challenges posed by the mines. cool the corrugated-iron shields behind The dollar loss was not the only con­ The problems are interesting, some and below which firefighters work to sequence of this act of sabotage: the remaining open despite the speed and remove debris by the use of caterpillar- heavy flows damaged the under­ tracked bulldozers, cranes and large ground reservoirs; plumes of smoke To water-cooled hooks. Getting the fire Christmas Tree El Cement and combustion products from the jetting straight up is almost always Ground---- flames created serious health and the first order of business. For inst­ environmental problems, not only in 3011-- ance, Red Adair in his successful quenching of the Devil's Cigarette Kuwait but at much larger dis­ Region of tances; and lakes of oil developed, Water Sand Lighter in Algeria (a blazing plume 3 more than a metre thick and many 300 It-- of 10 million m of gas per day), square kilometres in extent, creating Top of Dammam first drilled water wells to fill additional difficulties. polyethylene-lined reservoirs 10-ft Iraqi land mines and unexploded Burgan Reservoir deep and the size of three football coalition munitions in Kuwait were WeHhead Rating 2000 p.sJ. fields, about 30,000 m3 of water. expected to add to the hazard and (We hope that readers will tolerate delay, as were administrative im­ a mixture of English and metric pediments. The scale of the disaster units, English being conventional in was unique: there had never before the oil fields. Conversion is readily been more than five wells simul­ achieved as follows: 1 ( 42-gallon) 3 taneously out of control. Earlier 3100 II --- barrel = 0.159 m ; 1 inch = 2.54 em; 1 foot = 30.48 em; 1 pound per experience had shown that an ex- 9 5/8" Intermediate Casing pert well-control company could square inch (p.s.i.) = 0.0703 kg 2 2 typically kill and control a burning 3400 ft --­ cm- = 6,980m N .) Before he well in 2 weeks, although months Top of Ahmadi Shale snuffed out the fire, Adair cleared might occasionally be needed. With the site to table-top neatness and an estimated 18 teams potentially cooled the vicinity of the fire for available, it was believed that 700 days to ensure that there would be wild wells would take several years no re-ignition when the fire was put to control. Numerous ideas were out. The flame is snuffed out in the proposed by specialists to deal with classical method by exploding hun­ the problems of bringing the oil dreds of kilograms of high explosive fields under rapid control. But oil carefully shaped inside a thermally wells are far more complex than insulated oilfield drum supported by many realized and the vast majority a crane at the base of the flame, and of the ideas were poorly suited to Fourlh detonated from the safety of a the challenge. For example, the big trench or burrow at a distance of problem is not in extinguishing the hundreds of metres. fires, but in stopping the flow of oil FIG. 1 A typical oil well in the greater Burgan field, south Adair's biography, An American and gas with low risk to the well- of Kuwait city, not to scale. Hero, by P. Singerman (Little, NATURE · VOL 354 · 7 NOVEMBER 1991 11 © 1991 Nature Publishing Group COMMENTARY Brown, 1990) is a highly readable corresponding to about 4 p.s.i. stress per removed by explosives above ground account of the technology and of the foot of depth. The Christmas tree starts level, whereas others had the casing and remarkable people who have developed above the floor of a smaii concrete tubing severed in the well cellar. With and practiced the demanding profession cellar, typically 2 m in diameter, extend­ pipehangers gone the production casing of control of wild weils, often with an ing 2-3 m below ground, which reduced and the production tubing will drop into unbeatable safety record. Not one of the required derrick height during the the weii, damaging it, but not stopping Adair's team has died in fighting wild driiiing and casing of the well. Some the flow. Many wells are gushing free weiis. But the traditional approach typi­ Kuwait wells are 'sour', yielding substan­ from unimpeded bores at typical rates of caiiy takes much time in preparation, tial H 2S, a gas lethal at concentrations of one or two thousand cubic metres per and much water; it had been practised at 200 parts per million, and one that leads day. Others, whose jets impinge on most against five simultaneously burning wreckage or which are venting laterally, weiis, compared with the hundreds in are flooding oil at similar rates, which Kuwait. then burns (incompletely) near the ground in great pool fires. The thermal The sabotaged wells power from a weii flowing at this rate is The nature of the problems of gaining about 300 megawatts. Conical mounds of control of a sabotaged weii can be hardened coke wiii have accreted around understood by reference to Fig. 1. The many of the wellheads. The well-known weii has a production casing of 7-inch problem of clearing hundreds of tons of diameter extending nearly to the total driiiing rig from the weii is absent on depth of the weii, containing a 3.5-inch occasions like these, of course. production tubing; each tube is of wail thickness adequate for the expected cap­ Flow control ped pressure. Oil may be produced from the annulus between these two pipes in With destruction only of the gathering pipeline or of a valve on the Christmas additiona to the production tubing. Cellar Top tree above the lowest control valves, the Figure 1 shows the casing set for a well might be brought under control typical weii in the Burgan field of Kuwait, indicating the depth of the pro­ simply by closing one of these lower valves. But if there are no valves left on duction zone and other characteristics. a production casing, and no flange, a The weilhead pressure rating is 2,000 massive fitting must be assembled to be p.s.i., with a test pressure of 4,000 p.s.i .. Some weiis have weilhead pressures of fitted over the casing after preparation, First cooling, and usuaiiy after snuffing the more than 6,000 p.s.i. The conductor WellHead- flame. This phase of the operation is casing of steel tubing 20-30 inches in diameter is drilled or driven about 30 fraught with danger, for example, from feet into the ground before weii drilling ignition by equipment spark, by lighting begins to stabilize the driii rig. Cellar Base from dust or rain storms, or from static The weii itself consists of four to seven electricity. Casing/ With eroded pipe, a pit is usuaiiy dug concentric tubes, including the two de­ scribed above, that terminate at different to give access to the casing set at a depth FIG.