InterPore2018 New Orleans

Creep/swelling behavior of shale/clay: Discrete element modeling, based on Monte-Carlo technique

15 May 2018, 17:01

2m

New Orleans

Poster + 3 Minute Pitch MS 1.15: Soft porous materials Parallel 5-B

Speaker

Dr Srutarshi Pradhan (Researcher, PoreLab, NTNU)

Description

Creep/swelling of Shale-rocks create several problems [1] during underground drilling operations, such as stuck-pipe/drill-bit. However, creep/swelling of shale-rocks can close the gaps between rock (wellbore) and casing –therefore no cementing is needed – which can save a lot of time and money and such a “natural” closing ensures “no-leakage” during further drilling and production phases. The field experience reveals that some shale-rocks are good candidate for creep/swelling and some are not. There are several parameters influence the creep/swelling behavior, such as- porosity, clay-quartz contents, stress difference between field and drilling zone etc. Therefore, to plan a safe and efficient drilling operation through shale-rocks, we should understand the creep/swelling mechanism of shale/clay. In this work, we have introduced a discrete element model, based on Monte-Carlo technique. We define a probability of swelling for all the clay grains in the shale-rock sample that includes the effect of stress-difference, porosity, temperature etc. The time evolution of grain creep/swelling results in bulk creep/swelling behavior of the sample and the simulation result qualitatively matches with the observations of shale/clay swelling experiments [2,3].

References

1. E. Fjær, R. M. Holt, P. Horsrud, A. M. Raaen and R. Risnes, Petrolum Related Rock Mechanics (Elsevier, 2008).
2. M. Deriszadeh and R.C.K. Wong, Transp Porous Med (2014) 101:35–52 DOI 10.1007/s11242-013-0229-8.
3. E. Rybacki, J. Herrmann, R. Wirth and G. Dresen, Rock Mech Rock Eng (2017) 50:3121–3140.