Innovative Application on Dual Oil Producer Completion: Gas Lift for Lower Zone and Natural Flow for Upper Zone Extends Oil Production in Giant Middle Eastern Oil Field

Abstract

A giant oil field consisting of carbonate reservoirs in onshore Abu Dhabi has been provided with long term Field Development Plan, including several Dual Oil Producer (DOP) completions in formations Shuaiba and Kharaib, more specifically in zones A & B to maximize oil recovery. Upper Zone and Lower Zone B have been producing on natural flow using dual completions. This has been possible due to high reservoir pressures available since the beginning of the production. Conditions have changed, especially for the Lower Zone B, and reservoir pressure has been declining for the past years. As a result, several wells ceased to flow mainly due to lower pressure and/or higher water cut conditions. Therefore, Gas Lift has been selected as the preferred artificial lift method in lower zone B. The problem has been identified in current dual wells where Upper Zone is still producing but changing dual into Gas Lift single oil producer in lower zone B will translate into halt in oil production in upper zone, therefore reducing the oil recovery for Upper Zone. This is a consequence of the current practice of plugging and abandoning the Upper Zone. An innovative application for dual oil producer completion with Gas Lift mandrels in long string has been evaluated to keep both zones producing and extend the ultimate oil recovery of the current wells. Candidate selection, including analysis and workflow, will be presented in detail. Moreover, the design process, well modelling and installation will be addressed further in this paper.

The Optimal Development Strategy Selected for Layered Sandstone Reservoir by Creating a System Economic Model

“…To better understand key drivers for successful stimulation of multiple fractured horizontal wells, Mohammed et al researched the Montney Formation by comparing and contrasting the Upper and the Lower Montney completions and fracture stimulation statistical results with a reservoir and fracture simulation study [8]. Dashash et al researched highresolution sequence-stratigraphic correlation and facies characterization of the Upper Thamama (Lower Cretaceous) reservoir [9], Barragan et al researched innovative applications for extending the oil production of the gas lift for lower zone and natural flow for upper zone [10], and Dejam and Hassanzadeh derived a reduced-order model for tracer dispersion in stratified porous media and found that the field scale mixing may not necessarily originate from the Taylor dispersion and could be due to the modified advection terms and the cross-diffusive flux between the two layers [11] and so on [12,13]. However, the problems have not been solved that a quick method to determine whether use an old well or drill a new one still cannot be given.…”