Production in mature offshore Mexico fields is mostly driven by gas injected from surface. With time, injected gas flows directly through natural fractures in the low-pressure carbonate reservoirs, leaving oil trapped in the low-permeability matrix and reducing crude production. Over the past few years, the gas-oil contact has rapidly moved across those fields making conventional gas shutoff techniques both unsuccessful and uneconomic. An innovative approach introducing a fit-for-purpose polymer foam system (PFS) and its accurate placement using coiled tubing (CT) real-time telemetry addresses those challenges with an unprecedented success rate while optimizing both logistics and operational time. To selectively shut off unwanted gas in these naturally fractured reservoirs, the PFS was designed to have a high foam quality and low density. Thanks to a delayed crosslinker, this formulation enables deep penetration along the fractures and fissures before the gel strength develops. To ensure effective placement of the PFS and its activation at the right depth, CT downhole gauges monitor pressure and temperature throughout the pumping stages. Any deviation from the downhole schedule can swiftly be addressed to maximize shutoff effectiveness at depth. Monitoring of downhole parameters is not only instrumental to the PFS placement, it is also critical to other services associated with conformance operations. Thanks to the casing collar locator and gamma ray signals, it enables accurate depth control during perforating and stimulation phases. This system also facilitates the evaluation of the wellbore response after each main stage of the intervention. Finally, it can help perforate new intervals with minimum impact to the already pumped conformance treatment through the use of a new perforating firing head whose activation is controlled through fiber optics rather than triggered by hydraulics. The introduction of this methodology in offshore Mexico led to an increased success rate in gas shutoff operations. Of the nine wells that had interventions performed in 2015, eight were initially closed to production due to high gas production. Following the shutoff interventions, those wells were put back in production with an average reduction of 8.0 MMscf/d in gas produced per well and an average increase of 600 BOPD in oil produced per well. Near the end of the campaign, average oil produced per well reached 830 BOPD thanks to further improvements in the operational workflow. This approach constitutes a significant step forward in terms of efficiency and economic sustainability. The use of CT to perform all the stages of conformance operations greatly improved logistics on the platforms. In addition, the real-time monitoring capabilities of the system and flexibility of its downhole toolstring enabled an enhanced level of evaluation throughout the interventions, which, in turn, optimized the outcome and saved days of operation.

Today drilling wells is one of the biggest capital expenditures and is employed starting from exploration, delineation, initial wells for production, and fresh production incorporation when existing wells production have declined. The estimated cost for drilling new wells in Ayatsil field is around 20 to 25 MM $, which requires a high level of decision to achieve production goals without exceeding the budget assigned to the Ayatsil field. Therefore, to make the right decision requires an integration of multidisciplinary group of specialists (geologists, geomechanics, reservoir engineers, production engineers and drilling engineers) from well design to execution phases. This paper will illustrate the methodology and process applied by the operator to optimize the drilling stages and accelerate field production, as a result the operator developed the operational excellence project, that consist of five phases and being executed by a multidisciplinary project team. The drilling team has been successful in reducing the depth versus days curves from an average of 130 days in 2017 to an average of less than 58 days in 2022. The best performance achieved till now in terms of total meterage is 4,200 meters drilled in 51 days from the surface. The continuous improvement of the Ayatsil project has resulted in world class drilling performance. The success factors include standardized well design, performance improvement processes that was made possible by the multidisciplinary well decision team like, flat times efficiency. In addition, the outcome of this approach has resulted that 30 to 33 million dollars have been saved from the original budget in reduction of well costs and impulse the productivity of Ayatsil field.