"Common practice would demand redrilling every well to be repaired, but it seems probable that some simpler and cheaper method could be devised which would enable the operators to re-establish points of shut-off.
"Should the result of the work recommended on Alma Jr. No. 2 and Petroleum Development Company Well No. 28 indicate that the lack of uniformity of points of shut-off is responsible for the water conditions, shut-offs should be established in Red Bank No. 14 and Petroleum Development No. 14, in conformity with those of the Alma Jr. wells." Results.—Work was carried on at the two wells as recom mended. The work on Well No. 28 of the Petroleum Develop ment Company consisted of plugging off the deep-flowing salt water, well below the lowest oil measures. The work on this well was then suspended, as it was though that a better test could be made of the success of plugging after the work on Alma Jr. No. 2 was completed, than when the sands were being flooded from that well.
Work was begun on the Alma Jr. No. 2 well, February 25, 1917, at which time the 3 in. air line was pulled and an unsuccess ful attempt was made to loosen the 7% in. casing. A cement plug was found in the bottom of the 7% in. casing at 874 ft. The 7% in. casing was finally loosened with two 60-ton jacks, and after raising it 20 ft., the cement in the bottom was drilled out.
An attempt was made to plug the well as the 7% in. casing was withdrawn, but it was not successful because every movement of the casing caused the well to fill with sand through the perfora tions. The 7% in. casing was pulled, the perforated joints re placed with unperforated joints, and the casing run back into the well. As running sand had to be contended with all the way down, the work was slow, and finally, when the casing was down to about 830 ft., the string of tools was stuck in the hole by caving sand. Two weeks time was spent in fishing for the tools, which were finally recovered on April 30, 1917. After several days' work it was found to be impracticable to mud the hole while the sand was heaving in, so the 7% in. casing was pulled out and run back into the hole to a depth of about 702 ft., and thorough mud ding of the well was commenced.
The mode of operation adopted was to keep the tools swinging at or near the shoe of the casing, shovel in dry clay and allow a stream of water to run into the well. In this way it was hoped to mud the sands sufficiently so that the casing could be lowered without danger of freezing. By this method the casing was car ried down to 789 ft., where it froze after about 1000 cu. yds. of clay
had been put in. The hole was then drilled ahead to 88612 ft., using approximately another 100 cu. yds. of clay, and the process of plugging was begun. The hole was plugged solid from 886' 2 ft. to 826 ft. with clay, cobbles and manila rope. At this depth the well was shot with 30 lbs. of 60 per cent. dynamite the hole was cleaned out and 15 sacks of cement put in through tubing. A second shot was placed at 792 ft. (32 lbs. of 60 per cent. dynamite) and, after cleaning out to 801 ft., eight sacks of cement were put in through tubing. A third shot was put in from 767 ft. to 773 (50 lbs. of 40 per cent. dynamite), and the hole was cleaned out to 782 ft. Eleven sacks of cement were put in at this depth through tubing. A fourth shot (50 lbs. of 60 per cent. dynamite) was put in from 757 ft. to 765 ft. The hole was cleaned out to 765 ft.. and filled with clay and cobbles to 755 ft., and a fifth shot put in from 745 ft. to 752 ft. (50 lbs. of 60 per cent dynamite). The hole was then cleaned out to 755 ft. and tamped solid with clay and cobbles up to 735 ft. A shell containing 50 lbs. of 60 per cent. dynamite was then set on top of the plug and exploded. Follow ing this operation the hole was cleaned out to 735 ft., and after running water in for several hours 13 sacks of cement were put in through tubing. This cement filled the hole to about 722 ft. The hole was then filled up with cobbles, a heaving plug set at 702 ft., and the pipe perforated from 684 ft. to 702 ft.
The inaccuracy of the original records is shown by the fact that the well was found to be some 60 ft. deeper than reported.
Within a week after mud was started into the well it began to show in the fluid pumped from surrounding wells as much as a quarter of a mile away, both up and down the dip of the formation. As soon as neighboring wells showed mud pumping was discon tinued, so that the clay would not be unnecessarily drawn away from the well under repair.
About 1140 cu. yds. of clay were used in addition to several wagon loads of cobblestones and other materials. The work ex tended over a period of six and one-half months. The total cost was about $8,000, of which $4,400 was for labor and $2,500 for hauling clay.
A comparison of the condition of wells in the locality, both be fore and shortly after repair work, is shown by the following statement of production: The effect of the repair work was permanent. After about three years had elapsed, the group of wells was producing 50 bbl. of oil and 60 bbl. of water per day.