Energy Policy Act of 2005 (Ultra-deepwater and Unconventional Resources Program)
Novel Gas Isotope Interpretation Tools to Optimize Gas Shale Production
California Institute of Technology (Caltech)
Devon Energy Corporation
BJ Services Company
This proposal answers RPSEA 2008 Unconventional Onshore Program Solicitation asking for concepts for Shale gas production that could “Characterization of geologic, geochemical, geophysical, and operational parameters that differentiate high performing wells; Development of methods to accurately assess the potential of shale for gas production from common industry petrophysical measurements; Development of methods to plan, model and predict the results of gas production operations”.
Our main objectives for the proposed research and development program is to develop novel diagnostic tools so for predicting, monitoring and optimizing shale gas production. Using our unique field deployed gas isotope real time measurement device, one can quantify how much gas is retained by the shale since hydrocarbon generation ceased, how the gas is held in the reservoir and then released during production, and how the phase behavior of gas in the reservoir does change during production.
We will deploy a field real time isotope measurement analyzer for a high frequency real time gas isotope analysis. Using gas isotope, we should be able to differentiate a gas either stored as free gas in natural fractures and intergranular porosity, or absorbed onto kerogen and clay-particle surfaces. We can also quantify total gas volume based on the thermal maturation of shale and remaining gas potential. Then we can predict the life time of gas producing wells. Monitoring and evaluating the production schedule of free gas vs adsorbed gas can help an operator or a service company to associate the gas production pattern to the overall well completion and fracturing design for shale gas wells. Especially in a horizontal multi-stage frac completion, changes in fracturing treatment technology may lead to different ratios of free gas to adsorbed gas at different times during production history. By optimizing the completion design, it may be possible to achieve maximum gas production rate while minimizing the cost of completion per mcf of gas. Our industrial partners include Devon Energy, BJ Services and GeoIsoChem Inc., while BJ and GeoIsoChem will contribute 20% of industrial cost shares to this project (BJ 15%, GeoIsoChem 5%).
Principle investigator: William A. Goddard III (Caltech),
Co-PIs: Yongchun Tang (Caltech), Fausto Mosca (Devon Energy), David Curry (Devon Energy), Robert Braun (GeoIsoChem), Randy LaFollette (BJ Services), Qi Qu (BJ Services)