A Systematic Analysis to Select an Optimized Perforating Interval as a Key Factor for Improved Oil Recovery: Impact of Dynamic and Static Petrophysical Properties on Well Production

Abstract

AbstractUnexpected high water cut, sand production and low productivity have negatively affected multiple wells producing from reservoirs in the Apure Area fields of southwest Venezuela. As a result, multiple well interventions have been conducted which increase costs and delay oil production. Several of these wells are inactive today but could be potential candidates for reactivation by reperforating prospective intervals. In several cases, the selection of the perforated interval for these reservoirs is considered inefficient because the effects of multiple dynamic and static petrophysical properties are not considered in the current method, such as vertical permeability, anisotropy or pore throat size, among others. We propose a systematic analysis to optimize the interval to be perforated for inactive and new wells that will minimize such related production problems.The proposed analysis involves the incorporation of multiple variables (type of perforation, interval to perforate, distribution of reservoir fluids, fluid of completion, etc.) to consider the effects of the different petrophysical properties on well productivity. The latter are obtained by integration of rock-core data and conventional and advanced well logs acquired in open and cased hole. In addition, we conducted a sensitivity study to analyze other parameters, such as perforating method and production behavior. A technical analysis was performed to select the optimum design based on different conditions leading to a complete study. The results show that the optimum interval selection and type of perforation to be implemented should not involve only a simple net pay consideration but also multiple factors such as reservoir properties, reservoir fluids distribution and perforating method that play a key role in well production behavior. Finally, we present field applications that confirm the success of this method that enables the reliable selection of an optimized perforated interval.