The Lower Tertiary play in the Gulf of Mexico (GoM) was identified and completion approaches were developed in the early 2000s to address the complexities of the formation. The use of single-trip multi-zone completion technology was identified as a cost-effective solution to the stacked pay and has been applied by many operators in the GoM (Clarkson et al. 2008, Burger et al. 2010, Grigsby et al. 2016). As these fields have matured, some operators have experienced formation pressure depletion in some of the pay intervals within the proposed completion, challenging this common completion method.
The nature of a single-trip multi-zone completion dictates 1) all of the zones to be completed are perforated at the same time, and 2) the pressure gradients of these zones are similar enough that the well can be controlled by the well fluids. Early in the planning of this project, several of the zones within the pay interval of the target well were identified as depleted, which could result in fluid-loss-related control issues.
This paper will present a revised completion methodology to address the depletion problem. It will focus on the planning process, execution, and results of this type completion. It will review the identification of the problem, the different options identified to solve the problem, the planning that went into the preparation for the completion, the challenges that were seen during the completion process, and the results of the completion.
It is believed that although the challenge of depletion within the Lower Tertiary is new to this development, this situation will become more common as the Lower Tertiary fields are produced. It is the hope that this paper will assist the industry in dealing with this challenge.