DRILLING POLICY IN ZONE OF EDGEWATER The policy for wells which are drilled outside of the central dome and in the zone of edgewater calls for a water shut-off above the first oil zone and a production from this zone only, unless a solid oil string is cemented above the intermediate edgewater and a second water string cemented below same to produce from the second oil zone and protect the first zone.
This program is, however, modified on the edge of the field where the first zone itself becomes edgewater or commercially non-productive, in which case a conductor string is landed near the surface; first oil zone and intermediate water are cemented off behind the next string of casing, after mudding formations under pressure and cementing the water string with sufficient cement to seal both intermediate water sand and first oil sand. Production may then be obtained from the second oil zone, which is commercially productive further from the axis of the fold than is the first oil zone.
The following wells have been drilled nearly to the base of the second oil zone, and being located in the zone of edgewater in the intermediate edgewater sand, were compelled to plug off the second oil zone and produce from the first oil zone only: Standard Oil Company.
Nos. "Baldwin" 24 and 25, Sec. 1, T. 2 S., R. 12 W., S. B. B. and M.
No. "Baldwin" 43, Sec. 6, T. 2 S., R. 11 W., S. B. B. and M McGinley Oil Company.
No. 6, Sec. 6, T. 2 S., R. 11 W., S. B. B. and M.
Potter Oil Company.
No. 1, Sec. 6, T. 2 S., R. 11 W., S. B. B. and M.
No assurance can be given that the second oil zone is pro tected from infiltration in these wells by the plugging operations.
The following wells have been drilled on the edge of the field and have cased off the first oil zone, together with the inter mediate edgewater, on the basis that the first oil zone at such locations is commercially non-productive.