New Automated Work Flows Enhance Formation Evaluation
Authors: Carpenter Chris 
Published: October 2018

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 187040, “Dynamic Data Analysis With New Automated Work Flows for Enhanced Formation Evaluation,” by M.A. Proett, SPE, S.M. Ma, SPE, N.M.  Al-Musharfi, SPE, and M. Berkane, SPE, Saudi Aramco, prepared for the 2017 SPE Annual Technical Conference and Exhibition, San Antonio, Texas, USA, 9–11 October. The paper has not been peer reviewed.

Petrophysical work flows are designed primarily to process static data for traditional openhole logs, which can provide estimates of porosity, saturation, lithology, and mineralogy. However, these estimates normally have a high degree of uncertainty and formation testing and sampling (FTS) data often are required for reservoir-condition calibration. This paper bridges the gap between operational petrophysicists and FTS specialists, introducing an automated work flow by which petrophysicists can conduct FTS jobs.

Introduction

Wireline formation testers (WFTs) were commercialized in the late 1950s; drilling formation testers (DFTs) were introduced more recently. The primary benefits for FTS by means of wireline (e.g., WFT) or drillpipe (e.g., DFT) tools always has been a link between openhole log static volumetric formation evaluation and dynamic reservoir properties such as reservoir pressure, mobility, and fluid-sample composition, with many more applications under development using advanced testing tools and methods. However, FTS always has faced challenges with the integration of formation-tester data into the petrophysical work flow, limiting the ability to take full advantage of this valuable source of dynamic data. 

Current work flows normally involve having an FTS specialist evaluate openhole log analyses, plan testing and sampling jobs, monitor data acquisition and quality-control (QC) results, and report on the final data interpretation. Thus, an FTS specialist should hold a wide spectrum of expertise, including FTS-tool use and data analysis and openhole logging and log analysis, as well as reservoir engineering and reservoir dynamics. Consequently, few petrophysicists are truly qualified to be FTS specialists. Therefore, automating FTS work flows is desirable.

Automated FTS Work Flow

In recent years, new automated methods have been introduced to speed up FTS data delivery. In automated QC data processing, real-time pressure tests are given a rating on the basis of criteria such as pressure stability, temperature stability, drawdown mobility, radius of investigation, and supercharging. More recently, methods have been published that can identify test sequences automatically. Similar methods have been implemented in at least one commercial software offering that demonstrates the benefit of automating the tedious process of selecting testing events manually. By combining the automated QC with the test-event selections, the analysis of data can be automated for real-time monitoring and post-job data processing objectively. With the testing data being processed automatically and the valid or best results being selected from each test sequence, automatically identifying reservoir fluid-flow behaviors is possible.