(341aa) Design of Shale Gas Processing and NGL Recovery Plant Under Feed Uncertainty

Rajib Mukherjee^a,b,* and Mahmoud M El-Halwagi^b,c

^aDepartment of Chemical Engineering, University of Texas Permian Basin, Odessa, TX

^bGas & Fuels Research Center, Texas A&M Engineering Experiment Station, College Station, TX

^cArtie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX

Abstract

The dramatic increase in unconventional oil and gas wells has led to huge shale gas production. It is predicted that by 2035, shale gas will make up to 40% of the total US domestic gas produced [1]. One of the key challenges in processing shale gas is its varied flow rate and uncertain compositional behavior [2]. While the flow rate of a shale gas decreases drastically over a period of time, an optimized fracking schedule or optimized plant capacity selection using multiperiod simulation approach can be useful for mitigation [3, 4]. The composition of shale gas on the other hand differs from one well to another, depending on the geological formation and by the type of well that the gas comes from. Thus, the variation in composition provides a challenge in efficient design of a shale gas processing and natural gas liquids (NGLs) recovery plant. In this work, the we will present impact of feed composition variation of shale gas using uncertainty principal [5, 6]. A stochastic approach is used for shale gas characterization and its impact on the performance of gas processing and NGL recovery units are analyzed. The corresponding performance outcomes provide the distribution profile that is probabilistically characterized and design and performance targets that meets sustainability criteria (e.g. economic as well as environmental) are identified. From the analysis it is found that the plant performance meets the minimum return on investment (ROI) percentage under certain specific conditions, implying that the proposed processing plant is economically viable to implement only under certain situations. The economic and environmental performance at the values of the input variables without considering uncertainty is found to be significantly different from the mean value from stochastic analysis, suggesting limitations from traditional design approach. Three different design capacity are used for our analysis. Contrary to general belief, our analysis found that plants with better economic performance are also environmentally friendly.

Keywords: shale gas processing, acid gas removal, glycol dehydration, natural gas liquids (NGLs), design under uncertainty

[1] Stevens, P. (2012). The shale gas revolution: developments and changes: Chatham House London.

[2] Getu, M., Mahadzir, S., Long, N. V. D., & Lee, M. (2013). Techno-economic analysis of potential natural gas liquid (NGL) recovery processes under variations of feed compositions. Chemical Engineering Research and Design, 91(7), 1272-1283.

[3] Reddy Asani, R., Mukherjee, R., El-Halwagi, M. M., (2019), “Optimal Selection of Shale Gas Processing and NGL Recovery Plant from Multiperiod Simulation”, In preparation

[4] Al-Fadhli, F. M., Mukherjee, R., Wang, W., El-Halwagi, M. M., (2018), “Design of Multi-Period C-H-O Symbiosis Networks”, ACS Sustainable Chemistry & Engineering, 6 (7), pp 9130–9136

[5] Mukherjee, R., Reddy Asani, R., El-Halwagi, M. M., (2019), “Optimal Design of Shale Gas Processing and NGL Recovery Plant under Feed Stream Composition Uncertainty”, In preparation

[6] Mukherjee, R., & El-Halwagi, M.M., (2018), “Reliability of C-H-O Symbiosis Networks under Source Streams Uncertainty”, Smart and Sustainable Manufacturing Systems, Vol. 2, No. 2, pp. -132-153