Rigless Remote Intervention: A Case Study of Combo Unit Utilization in Mahakam Offshore East Kalimantan

Mahakam block has been producing for over 40 years and now is in declining phase. Daily drilling and well intervention operations are still actively carried out to sustain and prolong the natural decline curve. Efficiency measures are taken out in each and every aspect of operations to support the diminishing values. One of them is the reduction of offshore platform sizing. Future minimalist platforms have limited top deck space which will further be reduced by the prevalence of: 1. Fixed platform equipment (generators, crane, etc.), and 2. Hazardous area requirement for Zone 0, Zone 1, and Zone 2. The future minimalist platform has a deck space area of approximately 221 m2, not yet taken into account said the reduction factors. The presence of the hazardous area and fixed equipment can reduce the free deck space availability down to 20% from the total deck space. These platforms are not originally designed with well intervention work in mind. However, the past 40 years proves that well intervention should never be left out when extending well’s lifetime is the objective. Well intervention unit, depending on the intervention type, requires top deck space from 26 m2 up to 92 m2 of free space, and an additional 3-4 m2 for lifting, means such as mast unit if the platform does not have a crane. Moreover, in a remote intervention mode, where no supporting barge is present, space requirement above the top deck became crucial as there is no alternative to back load unit to the barge incase the top deck beingover crowded. To support the continuity of remote intervention being more efficient alternative to barge-supported operation, the well intervention team initiates the feasibility study using combo unit as a replacement for conventional slickline and electric line unit. There are three types of combo unit presented in this paper, 1. Split Combo Unit, 2. Combined Drum Combo Unit, and 3. Digital Slickline Combo Unit. These types of unit can reduce the deck space requirement by 30%, reducing number of personnel needed from eight (8) to five (5) personnel in a single shift, improving operation timing efficiency, and improves the contract administration aspect. Despite the seemingly positive results, there are still issues to be resolved, both technical and non-technical, for combo unit to be an all-rounder solution for wireline work. This paper shall provide an early level observation and analysis for the feasibility of combo unit as remote well intervention unit, starting from the methodology to the corresponding results and lesson learnt.