A New Diagnostic Method for Prediction of Producibility in Low Quality Reservoir of Minas Field Using Well-Log Data
Abstract
Formation evaluation with well-log data is primarily used as prediction tool to identify porous and permeable zone containing hydrocarbon. When reservoir quality becomes lower, challenges are increasing and underestimating of productive interval can occur. To address the needs for better estimation of identifying productive intervals in Low Quality Reservoir (LQR), new tool namely Hydrocarbon Potential Evaluator (HPE) was introduced. The HPE tool methodology was developed based upon an exclusive study by correlating initial well-production history to the Open Hole Log responses.
The focus area of this study is low quality reservoir in Minas field. Current completion strategy in Minas field is to open comingle between LQR and high-quality reservoir interval. This practice, in most cases has resulted smaller production contribution from LQR. Despite common consensus suggesting that Minas LQR is recognized to have very good potential in terms of oil production deliverability if it is opened using proper technique and strategy.
Conventional workflow for candidate selection has been employed by reviewing well data such as logs, core, Xsection, map and production data. This procedure is deemed tedious, time consuming and may prone to inconsistency and biased. Post-execution review on 13 LQR pilot wells, maximum success ratio is 46%, where only 6 wells are noticeably delivered oil gain while the remainders are considered failed or inconclusive.
Significant improvement is made after the utilization of HPE, the tool based on development of cut-offs from more comprehensive analysis of petrophysical data.HPE is functioned to classify as radar diagnostic and perforation recommendation color tagging which in turn will correlate with quality and producibility. Utilization of HPE tool has increased analysis objectivity and reduced workover selection time. Post-execution review on 13 LQR pilot wells using HPE tool has delivered 80% result match, whether such wells are confirmed to successfully produce oil or water.
