Drilling, other field work to boost Shell CO 2 production

Shell's McElmo Dome drilling program aims to step up CO₂ production for use in the Permian basin.
A unit of Shell Oil Co. has kicked off a five well drilling program in McElmo Dome carbon dioxide field of Southwest Colorado.
The new wells, the field's first in nearly 6 years, will help Shell Western E&P Inc. serve rising demand for CO₂ at Permian basin enhanced oil recovery (EOR) projects in Southeast New Mexico and West Texas.
Shell operates McElmo Dome with a 44% interest.

Coupled with compression additions and a CO₂well workover program, Shell expects the drilling program to boost McElmo Dome's CO₂ deliverability by early 1997 to more than 1 bcfd. That would nearly double the field's productive capacity of mid-1995.

Shell Western officials late last month estimated the field's CO₂ deliverability at about 700 MMcfd.

Each new well is expected to produce 50 MMcfd of CO₂from Mississippian Leadville pay. Shell also will add about 40 MMcfd of deliverability by replacing 41/2 in. production tubing with 51/2 in. tubing in four wells this summer.

Tim Bradley, manager of Shell's CO₂ business unit, said steadily rising CO₂ demand in the Permian basin in the past year nearly outstripped supplies.

"We project that new and existing CO₂ floods should quickly absorb our deliverability increase," Bradley said.

First well spudded

Contractor Parker Drilling Co., Tulsa, on May 31 spudded the 9 SC well-first in the five well program-at Shell's Sand Canyon well cluster near Cortez, Colo.

Shell expected to reach 8,000 ft projected depth on the development well by the end of June and planned to spud each of the remaining wells within the next 6 months.

Shell's CO₂ expansion at McElmo Dome comes less than a year after Amoco Production Co. began a $17.8 million drilling program to increase deliverability of the Bravo Dome CO₂unit in Northeast New Mexico (OGJ, July 17, 1995, p. 26). Amoco expected the 31 well program to increase Bravo's CO₂ flow by about 65 MMcfd to 400 MMcfd.

Shell Western in late June 1995 began implementing the first phase of a CO₂ EOR project on 540 acres in the southern part of Bennett Ranch Unit near Denver City in Yoakum County, Tex. McElmo Dome wells are supplying most of the CO₂ required for that injection program.

Shell's Bradley said more Permian basin producers are choosing to use CO₂ in EOR operations because:

Production from many Permian basin wells has been declining after years of waterflooding.
CO₂ has proven to be an effective way of increasing production, while CO₂ flood installation costs in the past 12 years have decreased substantially.
Shell reservoir characterization technology and financing packages have helped improve CO₂ flood economics.