Propagation of pressure drop in coalbed methane reservoir during drainage stage
Abstract view|441|times PDF download|167|times
Abstract
Numerical simulation was employed to investigate the propagation speed of pressure drop at the drainage stage in coalbed methane (CBM) reservoirs. A seepage model of single-phase water in CBM reservoirs was generated with the parameter from CBM well ZS39 in the Zhengzhuang block of the southern Qinshui Basin. The effects of stress sensitivity and reservoir properties on the pressure drop propagation process were analysed. Moreover the pressure drop funnel scale index was introduced to quantitatively characterize the propagation process. The results indicate that stress sensitivity cause the permeability form the permeability drop funnel, which is consistent with the shape of the pressure drop funnel. Under the constant bottom pressure, the propagation speed of the funnel will gradually decrease in both longitudinal and lateral direction. And the overall propagation speed rapidly increases first and then gradually decreases. In the scenario of steady decrease in the bottomhole pressure, the pressure drop speed shows an increasing trend in the longitudinal direction, and a decreasing trend in the lateral direction. The overall propagation speed of the pressure drop funnel increases all along. The reservoir pressure drop is positively correlated with the initial porosity, the initial permeability and the elastic modulus. For Poisson ratio, when the ratio is small, the reservoir pressure drop has a negative correlation. As Poisson ratio increases over 0.35, a positive correlation exists. It was found from the sensitivity analysis of reservoir pressure drop that petrophysical parameters have strong sensitivity to pressure drop, especially for permeability. Therefore, this work may provide insights into the CBM reservoir properties, and thus will be favorable for improving CBM recovery.
Cited as: Jia, D., Qiu, Y., Li, C, Cai, Y. Propagation of pressure drop in coalbed methane reservoir during drainage stage. Advances in Geo-Energy Research, 2019, 3(4): 387-395, doi: 10.26804/ager.2019.04.06
Keywords
Full Text:
PDFReferences
Adusu, P.T. Optimising candidate well selection for matrix stimulation-IPR approach. Paper SPE 198707 Presented at SPE Nigeria Annual International Conference and Exhibition, Lagos, Nigeria, 5-7 August, 2019.
Clarkson, C.R. Case study: Production data and pressure transient analysis of Horseshoe Canyon CBM wells. J. Can. Pet. Technol. 2009, 48(10): 27-38.
Clarkson, C.R., Qanbari, F. A semi-analytical method for forecasting wells completed in low permeability, undersaturated CBM reservoirs. J. Nat. Gas Sci. Eng. 2016, 30: 19-27.
Connell, L.D. A new interpretation of the response of coal permeability to changes in pore pressure, stress and matrix shrinkage. Int. J. Coal Geol. 2016, 162: 169-182.
Dejam, M., Hassanzadeh, H., Chen, Z. Semi-analytical solution for pressure transient analysis of a hydraulically fractured vertical well in a bounded dual-porosity reservoir. J. Hydrol. 2018, 565: 289-301.
Hu, H., Jin, J., Zhao, L., et al. Effects of pressure drop funnels model of different shapes on CBM well productivity. Coal Geology & Exploration 2019, 47(3): 109-116. (in Chinese)
Ibrahim, A.F., Nasr-El-Din, H.A. A comprehensive model to history match and predict gas/water production from coal seams. Int. J. Coal Geol. 2015, 146: 79-90.
Ide, T.S., Pollard, D., Orr, F.M. Fissure formation and subsurface subsidence in a coalbed fire. Int. J. Rock Mech. Min. Sci. 2010, 47(1): 81-93.
Li, J., Su, X., Lin, X. Relationship between discharge rate and productivity of coalbed methane wells. J. China Coal Soc. 2009, 34(3): 376-380. (in Chinese)
Liu, Y., Lou, J. Study on reservoir characteristics and development technology of coalbed gas in China. Nat. Gas Ind. 2004, 24(1): 68-71. (in Chinese)
Majdi, A., Hassani, F.P., Nasiri, M.Y. Prediction of the height of destressed zone above the mined panel roof in longwall coal mining. Int. J. Coal Geol. 2012, 98: 62-72.
Mazumder, S., Scott, M., Jiang, J. Permeability increase in Bowen Basin coal as a result of matrix shrinkage during primary depletion. Int. J. Coal Geol. 2012, 96: 109-119.
McKee, C.R., Bumb, A.C., Koenig, R.A. Stress-dependent permeability and porosity of coal and other geologic formations. SPE Form. Eval. 1988, 3(1): 81-91.
Mendhe, V.A., Kamble, A.D., Bannerjee, M., et al. Evaluation of shale gas reservoir in Barakar and barren measures formations of north and south Karanpura Coalfields, Jharkhand. J. Geol. Soc. India. 2016, 88(3): 305-316.
Meng, Z., Zhang, J., Liu, H., et al. Productivity model of CBM wells considering the stress sensitivity and its application analysis. J. China Coal Soc. 2014, 39(4): 593-599. (in Chinese)
Moore, T.A. Coalbed methane: A review. Int. J. Coal Geol. 2012, 101: 36-81.
Palmer, I., Mansoori, J. How permeability depends on stress and pore pressure in coalbeds: A new model. SPE Reserv. Eval. Eng. 1998, 1(6): 539-544.
Palmer, I. Permeability changes in coal: Analytical modelling. Int. J. Coal Geol. 2009, 77: 119-126.
Salmachi, A., Karacan, C.Ö. Cross-formational flow of water into coalbed methane reservoirs: Controls on relative permeability curve shape and production profile. Environ. Earth Sci. 2017, 76(5): 200.
Sang, S., Xu, H., Fang, L., et al. Stress relief coalbed methane drainage by surface vertical wells in China. Int. J. Coal Geol. 2010, 82(3): 196-203.
Seidle, J., Jeansonne, M.W., Erickson, D.J. Application of matchstick geometry to stress dependent permeability in coals. Paper SPE 24361 Presented at SPE Rocky Mountain Regional Meeting, Casper, Wyoming, 18-21 May, 1992.
Teyssedou, A., Onder, E.N., Tye, P. Airewater counter-current slug flow data in vertical-to-horizontal pipes containing orifice type obstructions. Int. J. Multiph. Flow 2005, 31(7): 771-792.
Wang, C., Shao, X., Sun, Y., et al. Production decline types and their control factors in coalbed methane wells: A case from Jincheng and Hancheng mining areas. Coal Geology & Exploration 2013, 41(3): 23-28. (in Chinese)
Wang, Y., Wang, C., Wang, F. Analysis on the relationship between pressure drop laws and production parameters of CBM well: A case study on the Baode Block. Oil Drill. Prod. Technol. 2019, 41(4): 502-508.
Yarmohammadtooski, Z., Salmachi, A., White, A., et al. Fluid flow characteristics of bandanna coal formation: A case study from the fairview field, eastern Australia. Aust. J. Earth Sci. 2017, 64: 319-333.
Refbacks
- There are currently no refbacks.
Copyright (c) 2019 The Author(s)
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.