The Delta Mahakam’s geology is characterized by multiple layers of thin, heterogeneous reservoirs separated by a few meters. These wells are traditionally perforated with the conventional wireline method. However, at reservoir porosities less than 11%, perforations yielded less than 60% of flowing probability. With the increase in drilling activity and the number of reservoirs with low porosities, we began to evaluate the effectiveness of perforating these reservoirs with abrasive jets perforation conveyed on coiled tubing (CT).
To improve depth accuracy and monitor real-time bottomhole conditions, the abrasive jet perforating tool was run on fiber-optic CT. Pressure measurements inside and outside the coiled tubing enabled the pumping rate of the abrasive fluid to be adjusted as necessary, improving perforating efficiency as well as the GR/CCL reading for the depth correlation.
This abrasive perforation method was applied in six different wells in Delta Mahakam field; the design, execution, and evaluation of this method is presented. From the first well to the last, this alternative perforating strategy helped increase reservoir production, improve cost efficiency, and by adding the real time monitoring system on coiled tubing it is proved of reducing the operational time by up to 45%. This method proved to be a viable alternative to wireline-conveyed perforating in the Delta Mahakam field.