Optimizing LWD Fluid Sampling With a New Transient Approach: The Reciprocal Contamination Derivative
- Camilo Gelvez (The University of Texas at Austin) | Carlos Torres-Verdín (The University of Texas at Austin)
- Document ID
- Society of Petroleum Engineers
- SPE Annual Technical Conference and Exhibition, 30 September - 2 October, Calgary, Alberta, Canada
- Publication Date
- Document Type
- Conference Paper
- 2019. Society of Petroleum Engineers
- Logging-While-Drilling, Transient Analysis, Reciprocal Contamination Derivative, Fluid Cleanup and Sampling, Reservoir Characterization
- 130 in the last 30 days
- 131 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 9.50|
|SPE Non-Member Price:||USD 28.00|
Successful in-situ fluid cleanup and sampling operations are commonly driven by a fast and reliable analysis of pressure, rate, and contamination measurements. Currently, techniques such as pressure transient analysis (PTA) and rate transient analysis (RTA) provide important information to quantify reservoir complexity, whereas fluid contamination measurements are overlooked for reservoir characterization purposes. The objective in this paper is to introduce a new interpretation technique to relate fluid contamination measurements with reservoir properties by identifying early- and late-time flow regimes in the derivative plots of reciprocal fluid contamination. Among several applications, this new transient analysis method is effective for improving logging-while-drilling (LWD) fluid sampling operations.
The derivative methods used in PTA and RTA inspired the development of the new fluid contamination interpretation method. Contamination transient analysis (CTA) evaluates transient measurements acquired during mud-filtrate invasion cleanup to infer reservoir geometry. We apply derivative methods to the reciprocal of the time evolution of fluid contamination to identify flow regimes in cases of water-based mud invading either water-or hydrocarbon-saturated formations. LWD operations are considered under a continuous invasion effect, i.e. the fluid cleanup procedure is performed while mud filtrate continues to invade the formation. This constraint brings about a significant technical challenge for LWD fluid sampling jobs. Alternatively, this new method could be integrated with other pressure transient techniques to improve the interpretation of measurements. For example, in a pretest case where the pressure transient does not achieve the radial flow regime, fluid cleanup could provide complementary information about late-time flow regimes to enhance the acquisition of measurements in real time.
We document synthetic and field examples of applications of a new interpretation method. Seven reservoir cases are simulated to obtain contamination data: (1) homogeneous isotropic reservoir, (2) formation thickness, (3) laminated formations, (4) geological faults, (5) mud-filtrate invasion (6) reservoir properties, and (7) permeability anisotropy. All these cases are compared for single-phase and multiphase flow during LWD fluid sampling operations. Additionally, field case studies are analyzed to highlight the value of the reciprocal contamination derivative (RCD) in real-time operations. Reservoir limits and features such as saturating fluid and depth of invasion are identified in the flow regimes detected with derivative plots of the reciprocal of the contamination. Consequently, LWD cleanup and sampling efficiency could be optimized based on contamination transient analysis by identifying the flow regimes taking place in the reservoir during filtrate cleanup, hence improving the prediction of the time required to acquire non-contaminated fluid samples.
The new approach of the reciprocal contamination derivative is an alternative way to optimize fluid cleanup efficiency and to quantify the spatial complexity of the reservoir during real-time LWD operations. In addition, this new technique enables the evaluation of reservoir properties in less operational time than PTA without the need of pressure build-up stages, increasing fluid sampling efficiency in terms of quality and time.
|File Size||2 MB||Number of Pages||14|
Arps, J. J. (1945). Analysis of decline curves. Transactions of the AIME, 160 (01), 228-247. Society of Petroleum Engineers. doi:10.2118/945228-G.
Agarwal, R. G., Gardner, D. C., Kleinsteiber, S. W., and Fussell, D. D. (1999). Analyzing well production data using combined-type-curve and decline-curve analysis concepts. SPE Reservoir Evaluation & Engineering 2 (05), 478-486.Society of Petroleum Engineers. doi:10.2118/57916-PA.
Bourdet, D., Ayoub, J. A., and Pirard, Y. M. (1989). Use of pressure derivative in well test interpretation. SPE Formation Evaluation, 4 (02), 293-302. doi:10.2118/12777-PA.
Fetkovich, M. J. (1980). Decline curve analysis using type curves. Journal of Petroleum Technology, 32 (06), 1065-1077. Society of Petroleum Engineers. doi:10.2118/4629-PA.
Galvan-Sanchez, F., Pragt, J., Vieitez, C., Patil, T., and Ganjoo, V. (2016). The effects of repeated interruptions during the clean-up cycle in a challenging logging-while-drilling sampling operation. SPWLA 57th Annual Logging Symposium, Reykjavik, Iceland, 25-29 June. Society of Petrophysicists and Well-Log Analysts.
Hadibeik, A., Proett, M., Torres-Verdin, C., Sepehrnoori, K., and Angeles, R. (2009). Wireline and while-drilling formation-tester sampling with oval, focused, and conventional probe types in the presence of water- and oil-base mud-filtrate invasion in deviated wells. SPWLA 50th Annual Logging Symposium, The Woodlands, Texas, USA, 21-24 June. Society of Petrophysicists and Well-Log Analysts.
Kristensen, M., Ayan, C., Chang, Y., Lee, R., Gisolf, A., Leonard, J., Corre, P.-Y., and Dumont, H. (2014). Flow modeling and comparative analysis for a new generation of wireline formation tester modules. International Petroleum Technology Conference, Doha, Qatar, 20–22 January. International Petroleum Technology Conference. doi:10.2523/IPTC-17385-MS.
Kristensen, M., Chugunov, N., Gisolf, A., Biagi, M., and Dubost, F. (2019). Real-time formation evaluation and contamination prediction through inversion of downhole fluid-sampling measurements. SPE Reservoir Evaluation & Engineering 22 (02), 531-547. Society of Petroleum Engineers. doi:10.2118/187432-PA.
Liu, N. and Oliver, D. S. (2003). Evaluation of Monte Carlo methods for assessing uncertainty. SPE Journal, 8 (02), 188-195. Society of Petroleum Engineers. doi:10.2118/84936-PA.
Prasad, T., Castillo, H. C., and Elshahawi, H. (2012). Effective mitigation of tool sticking risk in formation testing and fluid sampling operations. SPE Annual Technical Conference and Exhibition, San Antonio, Texas, USA, 8-10 October. Society of Petroleum Engineers. doi:10.2118/159246-MS.
Zhao, Y. and Reynolds, A. C. (2009). Estimation and removal of tidal effects from pressure data. SPE Journal, 14 (01), 144-152. Society of Petroleum Engineers. doi:10.2118/103253-PA.
Zuo, J. Y., Gisolf, A., Wang, K., Dubost, F., Pfeiffer, T., Dumont, H., Mishra, V., Chen, L., Agarwal, A., Ayan, C., and Mullins, O.C. (2016) Quantitative mixing rules for downhole oil-based mud contamination monitoring in real time using multiple sensors. Journal of Petroleum Science and Engineering, 137, 214-226.