Miscellaneous Subsurface Methods S3? 



of five to ten acres each. When the wells cease flowing, electric-motor- 

 driven pumping units are used. About 230 directional wells have been 

 drilled in the twelve years since the program was started. Plans are being 

 prepared for drilling a new off^-shore lease recently granted to the com- 

 pany. It will be necessary to drill a number of very high-angled wells to 

 exploit this submarine-oil formation since the lease to be developed lies 

 between one and two miles off shore from the proposed surface locations. 

 Records kept by the company on production costs show that wear on 

 pumping equipment is not greater than it would be in average vertical 

 wells because of the care used in executing the directional drilling. 



Development of offshore structures from littoral locations has been 

 practiced in the Wilmington, Long Beach, and Elwood fields, California. 

 Much work of this same type has been completed successfully along the 

 Gulf Coast of Texas and Louisiana. 



The drilling of relief wells is a spectacular and well-known applica- 

 tion of controlled directional drilling to the problem of bringing wild 

 wells under control. The first work of this kind was done by Eastman en- 

 gineers in the Conroe field in Texas in 1933 (fig. 264). A well cratered 

 and started uncontrolled production of oil at the rate of 6,500 barrels a 

 day. This well produced over 1,400,000 barrels of oil before being 

 brought under control, drawing heavily upon the producing formation of 

 the field. A relief well was spudded at a location 412 feet from the center 

 of the crater, and the hole was directed to very near the bottom of the 

 wild producer at a depth of about 5,100 feet. By pumping water into 

 the producing formation near the bottom of the cratered well, it was 

 possible to shut off the flow of oil completely. Elaborate precautions were 

 taken during the course of drilling the relief well to prevent the nearby 

 crater filled with oil from becoming ignited. The relief well later was 

 plugged at the point where the deflection started and redrilled as a vertical 

 well. It is producing today. 



When an uncontrolled well has not damaged the casing badly, it is 

 possible for competent fire-fighting crews to extinguish the fire and cap 

 the well. Once a well is badly cratered, a relief well is the only economical 

 means for placing the well under control. Since 1933 a number of relief 

 wells have been drilled, all successfully. They include wells at Laguna 

 Madre, Falfurrias, Fremont, and Silsbee, in Texas; Arcadia and St. Martin 

 Parishes in Louisiana; Cement field in Oklahoma; Leduc in Canada; and 

 a burning gasser in Medias, Roumania. 



Skill in directional drilling, together with very accurate well survey- 

 ing, is demonstrated in the drilling of successful relief wells. A typical 

 relief well is shown in section in figure 260. 



Different types of drilling to produce accumulations of oil about salt 

 domes are illustrated in figure 259. Several direction-drilling applica- 

 tions are shown. i5 is a well that continued in the salt mass to C without 

 breaking through the overhang because of its placement in relation to the 



