SPE Drilling & Completion
Volume 24, Number 2, June 2009, pp. 229-238

SPE-106707-PA

Critical Conditions for Effective Sand-Sized Solids Transport in Horizontal and High-Angle Wells

View full textPDF ( 629 KB )

DOI  More information 10.2118/106707-PA http://dx.doi.org/10.2118/106707-PA

Citation

  • Duan, M., Miska, S., Yu, M., Takach, N., Ahmed, R., and Zettner, C. 2009. Critical Conditions for Effective Sand-Sized-Solids Transport in Horizontal and High-Angle Wells. SPE Drill & Compl  24 (2): 229-238. SPE-106707-PA. doi: 10.2118/106707-PA.

Discipline Categories

  • 1 Drilling and Completions
  • 5 Production and Operations
  • 1.3.2 Horizontal/Multilateral Wells
  • 5.6.3 Slurry Flow and Erosion
  • 1.2.5 Materials Selection (Casing, Fluids, Cement)

Keywords

  • hole cleaning, sand, critical velocity, horizontal, drilling fluid

Summary

Effective removal of small, sand-sized solids is critical for successful drilling and completion operations in sand reservoirs. Recent experience in extended-reach drilling also indicates that inefficient transport of smaller cuttings is a main factor for excessive drag and torque. This study was undertaken to determine two critical conditions for efficient transport of small solids. The two conditions are represented by the critical resuspension velocity (CRV), the minimum fluid velocity necessary to initiate solids-bed erosion, and the critical deposition velocity (CDV), the minimum fluid velocity required to prevent bed formation.

Experiments were conducted in a field-scale flow loop (8 × 4.5 in., 100 ft long) to determine CRV and CDV for 0.45-mm and 1.4-mm sands in different fluids over a range of bed heights and hole inclinations. The results show that, depending on sand size and fluid properties, CDV is approximately two to three times larger than CRV. Water is more effective than low-concentration polymer solutions for bed erosion. However, polymer solutions are more helpful than water in preventing bed formation. This indicates the need for different drilling fluids for cleanout and drilling operations.

A mechanistic model was developed to predict CRV for a solids bed. Both experimental and theoretical results indicate the importance of interparticle forces that are incorporated into the model. The model accounts for drillpipe eccentricity in any direction in an annulus, which is consistent with experimental observations. The model predictions are in good agreement with experimental results. Existing CDV correlations developed for larger cuttings were verified by experimental data for sands. The differences are approximately 25%. Results in this study will be useful not only in drilling and completion through sand reservoirs, but also in extended-reach drilling and sand control.

© 2009. Society of Petroleum Engineers

View full textPDF ( 629 KB )

History

  • Original manuscript received: 2 February 2007
  • Meeting paper published: 31 March 2007
  • Manuscript approved: 25 February 2008
  • Published online: 1 June 2009
  • Version of record: 1 June 2009