Integration of Numerical Simulation and Wireline Formation Testing Measurements for Permeability Interpretation

Wireline formation testing (WFT) has gained increasing popularity in the oil and gas industry in the last two decades because of its economical and environmental benefits. Recently, there has been growing interests in using the WFT pumpout transient data to interpret formation permeability and productivity with the conventional pressure transient analysis (PTA). Such an interpretation is based on the assumption of perforating the entire pay zone interval, though it is suspected not to be the case in reality, especially in thick formations where a limited section is sensed by a WFT probe. As for the laminated formations, one challenge to determine thickness is the presence of vertical heterogeneity. In practice, it is extremely difficult to detect such a lamination by running the conventional openhole logs because of their insufficient vertical resolution. Therefore, it is of fundamental and practical importance to quantify the effective formation thickness in thick formation and determine the vertical communication of the lamination to accurately interpret formation permeability with WFT measurements. In this study, a high-resolution near-wellbore numerical model has been developed to simulate the fluid sampling process together with transient pressures at a flowing WFT probe. This newly developed model is validated analytically and then with the field data from the deepwater Gulf of Mexico. With the inherent noise added, the calculated pressure derivatives are used as a diagnosis tool to determine the effective formation thickness. As for laminated formations, history matching has been performed with the field data measured by a dual-packer WFT to determine the vertical communication between sublayers and then interpret the permeability for each flow unit. Various cases with lamination located below or at the same level with the dual-packer have been generated to examine the effect of lamination on WFT interpretations. It is shown from sensitivity analysis that effective formation thickness, which is defined as the maximum vertical thickness in the reservoir being sensed by the WFT device during a test within a given tool resolution, is a strong function of permeability anisotropy, flow rate, porosity and permeability, gauge resolution and probe location. All above-mentioned parameters which increase the effective formation thickness are inclined to obtain the true formation permeability. As for field cases, the permeabilities for two WFT tests, which are performed at two locations in the same well, are interpreted to be 14.0 mD and 10.6 mD, respectively. Such an interpretation reveals the difference in permeability between individual flow units. In a formation where lamination located below the dual packer, radial flow regime will develop when radial length of lamination is greater than the vertical interval and when complete circular shape of lamination is formed. Spherical flow regime is affected greatly by the lamination located the same level with the dual-packer. The integration of packer(s) and observation probes can be used to accurately indicate lamination and flow regimes.

Name thesis:degree_name

Master of Applied Science (MASc)

Level thesis:degree_level

Master's

Discipline thesis:degree_discipline

Engineering - Petroleum Systems

Grantor dc:publisher

Faculty of Graduate Studies and Research, University of Regina

Year dc:date.issued

2013

Author dc:creator

• Yang, Min

Advisor dc:contributor.advisor

• Yang, Daoyong (Tony)

Committee members dc:contributor.committeemember

• Torabi, Farshid
• Luo, Peng

Language dc:language.iso

en

DOI

https://doi.org/10.82465/4929

OAI identifier oai:identifier

oai:uregina.scholaris.ca:10294/5400