Abstract
Hydrate reservoirs with underlying natural gas are currently considered to be the most promising hydrate reservoirs for commercial exploitation. However, during the production process, the temperature-pressure conditions and multiphase flow conditions after mixing are complex due to the differences in the physical parameters of each layer of fluid, and it is much more difficult to predict the secondary formation of hydrates. In order to accurately calculate the hydrate generation regions, a new prediction model of wellbore temperature and pressure field under the conditions of deepwater dual-source co-production was proposed, and the distribution pattern of the hydrate generation region in the wellbore was investigated based on this model. The results revealed that in the process of deepwater dual-source co-production, due to the influence of deepwater low-temperature environment, the section of gas line above the mudline had an extremely higher risk of hydrate formation. For the section of wellbore below the mudline, the inflow of relatively low-temperature fluid from the hydrate layer caused a sudden temperature drop in the wellbore, resulting in a corresponding increase in the risk of hydrate formation. Meanwhile, the larger the production rate of hydrate layer, the more obvious the temperature drop was. Hydrate production increased from 2 thousand m3/d to 300 thousand m3/d, temperature drop increased from 2.8 ℃ to 7.1 ℃, the hydrate generation region expanded from 200 m–1780 m to 20m-1900m. With the increase of shallow gas production rate, the temperature in the wellbore rose, the cooling effect of hydrate layer fluid weakened, and the risk of hydrate formation decreased accordingly. Shallow gas production increased from 10 thousand m3/d to 600 thousand m3/d, temperature drop decreased from 3.1 ℃ to 1.5 ℃, no hydrate generation below the mudline, and hydrate generation area above the mudline shifted upward from 180 m–1770 m to 0 m–690 m. The increased in shallow gas water content removed hydrate generation risk from wellbores below the mudline, but had little effect above the mudline. Reduced gas-liquid separation efficiency resulted in increased liquid production in the gas pipeline, a shift in the phase equilibrium curve toward lower temperatures, and a slight reduction in the risk of hydrate generation. The results of this paper can provide a reference for the prevention of secondary hydrate generation in the wellbore of deepwater dual-source co-production.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Abbreviations
- A:
-
Area of the wellbore
- C:
-
Heat capacity
- E:
-
Volume fraction
- Fr:
-
Frictional pressure drop
- H:
-
Enthalpy
- k:
-
Thermal conductivity
- m:
-
Mass flow
- P:
-
Pressure in wellbore
- Qp:
-
Displacement
- r:
-
Radius
- T:
-
Temperature
- U:
-
Total heat transfer coefficient
- v:
-
Velocity
- ρ:
-
Density
- θ:
-
Wellbore inclination angle
- αp:
-
Gas-liquid separation efficiency
References
Sloan, E.D.: A changing hydrate paradigm—from apprehension to avoidance to risk management. Fluid Phase Equilib. 228–229, 67–74 (2005)
Jassim, E., Abdi, M.A., Muzychka, Y.: A new approach to investigate hydrate deposition in gas-dominated flowlines. J. Nat. Gas Sci. Eng. 2(4), 163–177 (2010)
Perfeldt, C.M., et al.: Oil and gas pipelines with hydrophobic surfaces better equipped to deal with gas hydrate flow assurance issues. J. Nat. Gas Sci. Eng. 27, 852–861 (2015)
Wu, Y.S., Pruess, K.: An analytical solution for wellbore heat transmission in layered formations. SPE Reserv. Eng. 5(4), 531–538 (1990)
Gao, Y.H., Sun, B.J., Xu, B.Y., Wu, X.R., Chen, Y., Zhao, X.X., et al.: A wellbore/formation-coupled heat-transfer model in deepwater drilling and its application in the prediction of hydrate-reservoir dissociation. SPE J. 22(3), 756–766 (2017)
Cheng, W.L., Han, B.B., et al.: Study on wellbore heat loss during hot water with multiple fluids injection in offshore well. Appl. Therm. Eng. 95, 247–263 (2016)
Lin, R.Y., Shao, C.B., Li, J.: Study on two-phase flow and heat transfer in offshore wells. J. Petrol. Sci. Eng. 111, 42–49 (2013)
Liu, Z., Sun, B.J., Wang, Z.Y., et al.: Prediction and management of hydrate reformation risk in pipelines during offshore gas hydrate development by depressurization. Fuel 291, 120116 (2021)
Moridis, G.J.: Numerical studies of gas production from methane hydrates. In: SPE Gas Technology Symposium. Society of Petroleum Engineers. SPE 75691 (2002)
Gao, Y.H., et al.: Two phase flow heat transfer analysis at different flow patterns in the wellbore. Appl. Therm. Eng. 117, 544–552 (2017)
Wang, Z.Y., et al.: A new hydrate deposition prediction model for gas-dominated systems with free water. Chem. Eng. Sci. 163, 145–154 (2017)
Aman, Z.M., et al.: Hydrate formation and deposition in a gas-dominant flowloop: Initial studies of the effect of velocity and subcooling. J. Nat. Gas Sci. Eng. 35, 1490–1498 (2016)
Wang, Z.Y., et al.: Modeling of hydrate layer growth in horizontal gas-dominated pipelines with free water. J. Nat. Gas Sci. Eng. 50, 364–373 (2018)
Liu, Z., et al.: Risk and preventive strategies of hydrate reformation in offshore gas hydrate production trials: a case study in the Eastern Nankai Trough. J. Nat. Gas Sci. Eng. 103, 104602 (2022)
Bondarev, E.A., Gabysheva, L.N., Kanibolotskii, M.A.: Simulation of the formation of hydrates during gas flow in tubes. Fluid Dyn. 17(5), 740–746 (1982)
Nicholas, J.W., et al.: Assessing the feasibility of hydrate deposition on pipeline walls—adhesion force measurements of clathrate hydrate particles on carbon steel. J. Colloid Interface Sci. 331(2), 322–328 (2009)
Creek, J.L.: Efficient hydrate plug prevention. Energy Fuels 26(7), 4112–4116 (2012)
Rao, I., et al.: Gas hydrate deposition on a cold surface in water-saturated gas systems. Ind. Eng. Chem. Res. 52(18), 6262–6269 (2013)
Sohn, Y.H., et al.: Hydrate plug formation risk with varying watercut and inhibitor concentrations. Chem. Eng. Sci. 126, 711–718 (2015)
Acknowledgement
The work was supported by the National Key Research and Development Program (2022YFC2806502), the CNPC's Major Science and Technology Projects (ZD2019-184-003), the National Natural Science Foundation of China (51991363, 52304016), the Major Scientific and Technological Innovation Projects in Shandong Province (2022CXGC020407).
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2024 The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Liu, P., Liu, S., Pei, J., Zhang, J., Fu, W., Wang, Z. (2024). Research on Hydrate Formation Risk in the Wellbore of Deepwater Dual-Source Co-production. In: Sun, B., Sun, J., Wang, Z., Chen, L., Chen, M. (eds) Proceedings of the Fifth International Technical Symposium on Deepwater Oil and Gas Engineering. DWOG-Hyd 2023. Lecture Notes in Civil Engineering, vol 472. Springer, Singapore. https://doi.org/10.1007/978-981-97-1309-7_25
Download citation
DOI: https://doi.org/10.1007/978-981-97-1309-7_25
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-97-1308-0
Online ISBN: 978-981-97-1309-7
eBook Packages: EnergyEnergy (R0)