The Mahakam delta in east Kalimantan, Indonesia, yields gas as the main hydrocarbon production with giant reservoirs ranging from shallow to very deep zones. Reservoirs consists of clean sandstone with high permeability. Due to the field maturity, production gradually moved from the deep, consolidated zones into very shallow, unconsolidated zones. Sand production often causes significant problems at the surface when the well is online. The best approach to sand control is to keep it inside the reservoir, because it could create problems not only at surface but within the wellbore as well. Sand consolidation has been a common approach applied in Mahakam field for more than a decade. Several products have been utilized, including laboratory testing and field trials. The case history is based on a well that had been treated using 2 different sand consolidation products in the past, but both eventually produced inadequate results. Sand continued to break through after each treatment, hence the reserves could not be drained in full. Since the reservoir still had promising reserves, another remedial sand consolidation treatment was planned. This treatment was executed by utilizing a tension packer with a J-slot mechanism in order to focus injection of the resin into the zone of interest. Additionally, there was a challenge with another open zone above the subject interval. The remedial sand consolidation treatment using a resin-based chemical delivered excellent results. Even though this reservoir had been exposed to 2 different chemical treatments in the past, by using the resin-based sand consolidation product, the well was still able to be produced at target rates without sand production. In conclusion, resin-based sand consolidation solutions can unlock prolific reserves that may have been a significant challenge with traditional methods.

Declining of shallow reservoir reserve urges efficiency effort to switching well architecture from zone-selective gravel pack completion to non-selective tubingless completion. However, zone management in tubingless completion is not as simple as sliding sleeve manipulation in gravel pack well. It requires proper zone isolation of closed zone such as setting plug, tubing patch, or squeezed cement. Therefore, optimum zone management need to be identified to be consistent with cost efficiency effort. Study in determining optimum zone management captured two nearly identic case of 3 zones of selective well and non-selective well. The well cost, production, and its net present value was compared to evaluate how the reservoir production is managed. Although selective well has higher initial well cost, but operation cost during the production is significantly low. On the other hand, even non-selective well has lower initial well cost, due to complication on zone management, non-selective well has higher operation cost. The total cost of problematic non-selective well could nearly reach the selective well cost. The complication is identified as downward movement, i.e. re-accessing previously isolated lower zone and isolating upper zone at once. However, this study suggests that strictly following bottom-up production strategy could potentially avoid the complication by 23% more efficient in production and cost index. Well cost efficiency is not only determined by lower initial well cost. All operating cost during production must be also considered. Optimum well management for both type of completion is a key parameter in order to control the cost efficiency effort. Therefore, well completion design selection must consider not only the cost and production, but also the operation excellence and capability during managing well production in its lifetime.