Retrievable Socket Electronic Memory Recorder as a New Method of Bottom Hole Pressure and Temperature Survey in a Mature Field

Abstract

This paper presents valuable new method from Pertamina Hulu Rokan Zona 4 in bottom hole pressure and temperature (BHPT) survey. Nowadays, the conventional method and gradient pressure acquisition is only able to be done by using slickline after swabbing job, because during swabbing job, the swabbing tool string is used inside the tubing. Unfortunately, there are missing data when influx from reservoir occurred, due to the shut-in condition may not always represent overall characteristic of well. Retrievable Socket Electronic Memory Recorder (Retrisock EMR) is consisted of seating parts with deliverable and retrievable mechanisms. Engineering design was done to ensure it compatible for acquiring data during swabbing job without slickline unit. Retrisock EMR is put inside tubing, it is possible to record data since run in hole tubing, pressure test packer, swabbing job, pressure build up and static gradient pressure temperature. It could be retrieved without pull out tubing from well to download the data, nevertheless, the data may be uncertain for further analysis. The advantage, it could be put back into tubing by using sand line rig. Pressure and temperature were obtained during swabbing job represent the influx from reservoir into well. The graph of pressure can be approached as a well test, such as modified isochronal test which can be processed to pressure transient analysis for further determination of skin value, reservoir boundary and permeability. Combination of fluid total volume during swabbing job and pressure transient analysis result become reference whether well stimulation is needed or not, before putting on production well. Result of static gradient pressure analysis will estimate the static fluid level also could be used as measured gradient of fluid in well for calculating inflow performance relationship (IPR) precisely. The result of implementation in Talang Akar Formation, Benakat Barat Structure, well BKB-272 increased production significantly from 600 BFPD to 800 BFPD after evaluated by using data from Retrisock EMR measurement. Two more promising benefits of Retrisock EMR are time and cost efficiency. Based on study and implementation, it can reduce operation time up to 10 hours. Then, the impact of faster operation time is less operation cost Tool and method presented in this paper provide valuable concept for well optimization in developing BHPT survey before and after stimulation to compare the reservoir influx without pull out tubing string and slickline. Another opportunity is BHPT survey without shut in the well in oil well producer while it on production by using artificial lift electric submersible pump (ESP) that was not equipped with downhole sensor as real time monitoring tool.