Abstract

This paper describes the application of a new numerical model to simulate any work over plans in order to assess the work over efficiency and the well productivity enhancement, prior to operations commencement.

A case study is discussed, where an operator in Egypt had a plan to improve the productivity of an oil well producing from a multi-layer reservoir, where a low productivity layer had been previously identified and characterized by multiple techniques.

It was critical for the operator to enhance the productivity across this layer and to identify the appropriate remedial action (water shut off, re-perforate, or stimulation) that could impact the whole field production performance. The operator had decided to re-perforate and add new perforations to the low productivity layer.

The numerical simulation model was hence applied to assess work over techniques and to determine the most suitable remedial action for implementation. The simulation result of reperforation and adding new perforations showed water cut drop by 6% with an increase in oil rate by 538 b/d and in water rate by 348 b/d compared to the initial profile identified by production logging. The result of the numerical simulation model suggests that the low productivity layer should be considered as a candidate for stimulation (fracturing/acidizing).

When the operator attempted to re-perforate the low productivity layer, the production performance after the re-perforation did not show a major improvement, as the water cut decreased by 6% only with a small gain in oil rate, which is in agreement with the simulation model outcome.

The operator understood the reason for the field wide low productivity from this layer and hence obtained a key to unlocking the reserves contained in this layer across the whole field in future field development plans.

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