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

A growing number of low-frequency passive seismic surveys over proven oil and gas fields throughout the world have shown the presence of anomaly spectra (between 2–4 Hz). These signals are known as hydrocarbon microtremors, and the HyMAS (Hydrocarbon Microtremor Analysis) method has been widely used and developed by Spectraseis as a complement method for direct hydrocarbon indicators (DHI). This method, which is completely passive and does not require seismic artificial excitation sources, is useful for optimizing well placement during exploration, appraisal, and development for the oil and gas fields. We conducted several signal attributes provided for low-frequency passive seismic data that resulted in a better correlation between the presence of hydrocarbons in the subsurface and the observed spectral anomalies. In this study, we measured the attributes for 121 stations with two proven hydrocarbon production stations among them. We mapped each attribute value and interpreted the results based on spectral and polarization attributes from the proven hydrocarbon production stations. We also included the analysis of noise identification from the investigation site. Using the results, we combined each mapped attribute and made a spatial scoring map that provided the consistency level of each attribute for the DHI. This map provides a quick look to find an area of interest for further exploration which could be used for new optimized well placement during exploration.

An increasing demand for oil and gas production undoubtedly triggered innovation in exploration studies to find new hydrocarbon reservoir. Low-frequency passive seismic method named Hy MAS (Hydrocarbon Microtremor Analysis) is a new method invented and developed recently by Spectraseis which provide a quick look to find new hydrocarbon reservoir prospect area. This method based on empirical study which investigated an increasing of spectra anomaly between 2 - 4 Hz above reservoir but missing from the measurement distant from the reservoir. This method is quite promising because it has been used as another DHI (Direct Hydrocarbon Indicator) instead of active seismic survey which has some problem when applied in sensitive biomes. Another advantage is this method is completely passive and does not require seismic artificial excitation sources. In this study, by utilizing many attributes mentioned in the latest publication of this method, we try to localize new hydrocarbon prospect area outside from the proven production field. We deployed 63 stations of measurement with two of them are located above the known reservoir production site. We measured every single attribute for each data acquired from all station and mapped it spatially for better understanding and interpretation. The analysis has been made by considering noise identification from the measurement location and controlled by the attribute values from the data acquired by two stations above the reservoir. As the result, we combined each attribute analysis and mapped it in weighted-scoring map which provide the level of consistency for every single attribute calculated in each station. Finally, the new reservoir location can be suggested by the station which has a weighted-score around the values from the two production reservoir stations. We successfully identified 5 new stations which expected to have good prospect of hydrocarbon reservoir.