This paper summarizes the results obtained from the preliminary cementing of wells in an effort to cut off the bottom water. The object of this work was two-fold:
To prevent the oil sand from becoming flooded.
To plug off bottom water, thereby preserving the individual well and reclaiming production.
Valuable suggestions and help have been given by the following named: Messrs. Kyle and La Velle, of the U. S. Bureau of Mines; Magnolia Petroleum Co.; Freed Oil and Gas Co. The cementing work was carried out under the personal supervision of L. J. Snyder.
In an unpublished paper on the "Water Problem in the Augusta Field," S. K. Clark reaches the following conclusions:
That the great amount of water present is bottom water, occurring in the Varner sand, the main producing or the 2500-ft. horizon.
That the only striking connection between structure and water is in the area of the marked fault on the Ralston, E. C. Varner, and F. Varner leases in sections 8, 9, 16 and 17.
That the oil occurs in porous streaks, generally separated by fine-grained, well cemented sand, which is barren. Possibly two or three such pay streaks may be found. That under a pay, fine-grained sand occurs, which is presumably barren at the time of drilling, but soon reveals water.
The writer takes partial exception to the last point, because well defined shale, slate, lime, or hard sand breaks have been encountered in a great many cases, separating the pay streaks under which water is often found. This is not an invariable occurrence, as cases have been noted when the oil has been followed immediately by water in the same stratum.
In an effort to overcome the water menace, the following methods of plugging were tried:
Plugging with wood, lead, and limit plugs.
Plugging with sand pumpings.