EXHIBIT 21.1 SUBSIDIARIES OF NEWPARK RESOURCES, INC. 1. BATSON-MILL, L.P. 2. CHESSHER CONSTRUCTION, INC. 3. CONSOLIDATED MAYFLOWER MINES, INC. 4. DARCOM INTERNATIONAL, L.P. 5. EXCALIBAR MINERALS, INC. 6. EXCALIBAR MINERALS OF LA. L.L.C. 7. HYDRA FLUIDS INTERNATIONAL, LTD. 8. INTERNATIONAL MAT, LTD. 9. IML DE VENEZUELA, LLC 10. MALLARD & MALLARD OF LA., INC. 11. NES PERMIAN BASIN, L.P. 12. NEWPARK CANADA, INC. 13. NEWPARK DRILLING FLUIDS, LLC 14. NEWPARK ENVIRONMENTAL SERVICES, L.L.C. 15. NEWPARK ENVIRONMENTAL MANAGEMENT COMPANY, L.L.C. 16. NEWPARK ENVIRONMENTAL SERVICES MISSISSIPPI, L.P. 17. NEWPARK ENVIRONMENTAL SERVICES OF TEXAS, L.P. 18. NEWPARK HOLDINGS, INC. 19. NEWPARK SHIPHOLDING TEXAS, L.P. 20. NEWPARK TEXAS L.L.C. 21. NID, L.P. 22. OGS LABORATORY, INC. 23. SHAMROCK DRILLING FLUIDS, INC. 24. SOLOCO, L.L.C. 25. SOLOCO TEXAS, L.P. 26. SUPREME CONTRACTORS, L.L.C. 27. NEWPARK ITALIA, S.R.L. 28. AVA, S.p.A. 29. AVA ROMANIA 2000 S.R.L. 30. AVA AFRICA S.A.R.L. 31. CRILIO DUE EXIM S.R.L. 32. EUROCONTINENTAL DF GMBH 33. PERFO SERVICES S.P.A. 34. AVA TUNISI S.A.R.L. 35. AVA INTERNATIONAL LTD. 36. AVA ALGERIE E.U.R.L. 2