Drilling and completing wells for high productivity in the Point McIntyre field: Strategy, implementation and verification

A proactive approach to economically improving well productivity was undertaken at the beginning of the development drilling program in the Point McIntyre field on the North Slope of Alaska. This paper describes the comprehensive approach, laboratory tests, field implementation, and well test verification of reduced skin damage. The approach was a combination of a minimally damaging KCl mud with limited leakoff, KC1 in the cement and spacer, rapid drilling rates, and deep perforations. Laboratory tests of the rock and mud were performed before the onset of the drilling program, to identify potential damage mechanisms and to select the least expensive, least damaging, drilling mud. Field procedures were developed which ultimately led to open-hole displacement of freshwater mud to KCl mud just above the pay, which reduced the incremental cost by a factor of 2. The success of the drilling and completion strategy was demonstrated using pressure buildup tests to measure skin. Inexpensive pressure buildup tests were conducted prior to field startup, using in-house personnel and equipment, in addition to more conventional testing after field startup. Development well skins were compared with those of previous exploration wells and with water injectors which were drilled with a common low-solids non-dispersed freshwater mud.more » Although this reservoir would normally be identified as particularly damage-prone, use of KCl mud helped improve well productivity by almost 60% over wells drilled with the freshwater mud commonly used in the region. The well test and productivity data clearly justified the additional cost of using the more expensive drilling mud. Costly well stimulations were avoided, and infill drilling was deferred.« less