This paper is a review of the techniques that have caused a large improvement in drilling and completion performance on the Goodwyn A Platform North-West Shelf, Australia. The collective effort of Well Construction professionals using these techniques has resulted in the drilling of a 6263m (20,550') TD well with a horizontal step out of 5200m (17,060'), at a tangent angle of 67° in 39 days from spud to well handover. This was 31% under P50 AFE time estimate.
The paper will describe a method to produce systematic, steady and sustainable improvements to Well Construction operations. The methods described are a way of harnessing the collective brainpower of Well Construction professionals and focus that energy towards rigorous analysis of problems or areas of potential improvement, then systematically working through and implementing solutions.
The Technical Limit methodology and Performance Improvement Groups (PIGs) are best suited for complex, high cost drilling projects, typically ERD developments, high cost MODU exploration or subsea operations.
In addition, other tools such as Hazard Management, Learning System and Planning Processes which contributed to success are explained.
Goodwyn Phase 1 consisted of 13 wells and ended in April 1998. The need for performance improvement was evident as, for example, all the last 6 wells overran the AFE estimates, by an average of 68%. The wells had been challenging with horizontal step outs up to 7.3 km (24,200 feet), however it was evident that processes were not in place to properly handle these challenging wells. In subsequent investigations it was found that the root causes for this poor performance inevitably was related to planning, specifically a lack of detailed planning, short lead times available for planning, limited number of personnel and no formal processes for hazard management and mitigation.
To improve performance the following were implemented:
Use of the formal Technical Limit method;
Performance Improvement Group (PIG) processes; and
Changes to the work practices resulting in a work culture that practiced hazard management, planning and learning.
In addition, the Woodside Well Construction Management System had been rewritten and provided a valuable set of guidelines that provided consistency between Well Construction teams.
Goodwyn Phase 2 started in October 1998 and 4 wells were drilled. This resulted in 3 out of the 4 being under AFE time estimates, the last of which (Goodwyn 17) was drilled and completed 31% under the P50 time estimate. Goodwyn 17 had a Total Depth of 6263 metres (20,550 feet), a horizontal step out of 5200 metres (17,060 feet) and was drilled from spud to handover in 39 days. The first two wells had horizontal sections of up to 2300 metres. Refer to Table 1 for results. Note that Down Time is defined as any deviation from planned. Down Time was not used as a Key Performance Indicator as honest and critical reporting is the feedstock of the improvement process.
Refer to fig.1 for a graphical demonstration of the improvement made from Phase 1 to Phase 2. It can also be seen that a continual improvement trend is evident.