|
First development well spud at Phillips Alaska’s Meltwater development Twenty-six wells planned, 17 this year; Bermuda main accumulation at southwest Kuparuk pool; thinner Cairn will also be tested Kristen Nelson PNA Editor-in-Chief
The first Meltwater development well was spud at the end of April, Phillips Alaska Inc. officials said May 7 at an Alaska Oil and Gas Conservation Commission hearing on the company’s application for pool rules and an injection order for the Kuparuk satellite accumulation. Some 26 wells are planned this year and next, all from the single drill site built this winter. Meltwater is expected to be on line later this year.
Phillips is the major owner and operator at Meltwater, which is at the southwest corner of Kuparuk. Phillips said Meltwater development will be from the Bermuda sand accumulation, drilled in the Meltwater discovery wells in 2000, but the thinner Cairn south interval to the east of Bermuda will be tested this summer.
Both the Bermuda and Cairn accumulations are “very discrete” Phillips said, with sandstone reservoirs the result of slope apron deposits of sand analogous to the Tarn reservoir 10 miles to the north. The makeup of the sands at Meltwater is also very similar to those at Tarn, Phillips said. Average porosity at Meltwater is 20 percent; average permeability is 10-15 millidarcys.
Meltwater is defined by the Meltwater North 2A exploration well, where the Meltwater reservoir is between 4,958 feet and 5,297 feet subsea. Phillips said that the geographic extent of the Meltwater pool was sections 1-36 of 8N, 7E, UM.
Bermuda is the primary target at Meltwater, Phillips said, but Cairn production is also possible. Phillips said there were fewer opportunities for Cairn targets and more risk. Cairn is a separate, thinner, accumulation.
A portion of the hearing was closed to all but Phillips and commission staff, but in a summary of confidential data Phillips said there is upside potential in the area — prospects which have not yet been drilled. Miscible injection EOR from beginning The estimate for original oil in place at Meltwater is 132 million barrels in the Bermuda interval, with some 52 million barrels expected to be recoverable.
Phillips plans to use miscible injectant at Meltwater for enhanced oil recovery from the beginning of production, and said it expects 9 percent incremental recovery over water flood through use of a water alternating miscible gas flood.
Use of miscible injectant at Meltwater will also remove gas from the Kuparuk field, which is gas constrained, Phillips said. Keeping the MI for use at Kuparuk would increase recovery there slightly, but that recovery would be offset because gas handling is limited at Kuparuk.
Development drilling has begun at Meltwater. The first well was spud at the end of April and Phillips said it expects to drill 17 wells this year, with emphasis on the sweet spots. Cairn will also be tested early in the process. Phillips said there will probably be a drilling break during the 2001-02 exploration season, and then another nine wells will be drilled in 2002.
Aggressive initial MI injection is planned, followed by a lean gas sweep late in the life of the field to recapture natural gas liquids from MI. A two to one production to injector well proportion is planned initially, with conversion of producers to injectors expected to result in a one to one ratio later in field life. Some gas lift required About one-half of the wells are expected to flow on their own, but wells will be equipped for gas lift and Phillips said it would use miscible injection initially for gas lift. Jet pumps will be used for weaker wells, and Phillips said the warm injection water will also have the advantage of helping to keep paraffin from building up in tubing. The crude at Meltwater is 3.5 percent wax by weight.
Cairn is about 200 feet above Bermuda, and Phillips said it was asking the commission for no annular isolation for 200 feet above Bermuda, preserving the opportunity to test Cairn out of Bermuda-target wells. Phillips said that significant information is expected on Cairn within a couple of months, with a Cairn well planned for this summer in an area where the company doesn’t anticipate encountering Bermuda.
Phillips also said that while 100 acre spacing would be optimum economically, it is asking the commission for 10 acre spacing to allow it to go after areas of the accumulation with communication problems.
Well design is based on Tarn, with both standard and slim hole designs. The 2P pad at Meltwater has a trunk and manifold design similar to Tarn, with a 20 foot minimum between wells. Phillips described 2P as a fairly bare bones drill site. Kuparuk to be expanded Phillips said an application to expand the Kuparuk River unit and to establish a Meltwater participating area is expected to be submitted to the Alaska Department of Natural Resources Division of Oil and Gas in May. Meltwater is at the southwest corner of Kuparuk.
Phillips said in written testimony that a portion of the Meltwater accumulation extends outside the greater Kuparuk area onto a lease owned by Phillips Alaska and BP Exploration (Alaska) Inc. and all of the greater Kuparuk owners except Exxon Mobil Corp. (which has a 0.3648 percent working interest in the greater Kuparuk area) have agreed to buy interest in the lease.
An estimated 40.6042 percent of total Meltwater net sand volume is on the lease. Phillips said the percentage ownership at Meltwater is a function of lease ownership and is similar to but not exactly the same as other Kuparuk River satellites. Production ownership breaks out approximately: 55.4 percent Phillips; 39.3 percent BP; 5 percent Unocal; and less than 1 percent combined for Chevron and Mobil heritage acreage.
| 