Use of successive pressure build-up test data from well A-1 H in the Snadd field to obtain dynamic reservoir information

Abstract

Well A-1 H in the Snadd field was put on test production at the beginning of 2013. Since then, a series of pressure build-up tests has been conducted. These aimed to allow the evaluation of the quality of the Lysing prospect and the viability of future production from the field. In this study, the pressure response from nine pressure build-up tests throughout the period of ca two years is examined. These were conducted staring in February 2013, and lasted until October 2014. The analysis, run with Saphir software, reveals information about dynamic reservoir parameters, such as permeability, permeability thickness, skin and turbulence factor. The tests show good repeatability, as the pressure derivative overlay can be observed. The value of permeability thickness from tests oscillates around 3300 md.ft, whereas the value from the last test is considered to be the most reliable, 3620 md.ft. From the analysis of the extended test – PBU-9, a clear boundaries’ response was detected. Discussions lead to conclusion that this might be the aquifer response, the distance to the aquifer was estimated to be 4800 ft. The change of the average reservoir pressure, p* with time was determined and it creates a reasonable trend for production from the field. In further studies the obtained pressure values can be a foundation for material balance calculations.