Reference C 16 -C 18 Internal Olefin Drilling Fluid Formulation

The reference C 16 -C 18 internal olefin drilling fluid used to determine the drilling fluid sediment toxicity ratio and compliance with the BAT sediment toxicity discharge limitation ( see § 435.13) and NSPS ( see § 435.15) shall be formulated to meet the specifications in Table 1 of this appendix. Drilling fluid sediment toxicity ratio = 4-day LC 5 . of C 16 -C 18 internal olefin drilling fluid/4-day LC 5 . of drilling fluid removed from drill cuttings at the solids control equipment as determined by EPA Method 1644: “Method for Conducting a Sediment Toxicity Test with Leptocheirus plumulosus and Non-Aqueous Drilling Fluids or Synthetic-Based Drilling Muds” after sediment preparation procedures specified in EPA Method 1646, which are published as appendices to Subpart A of this part and in “Analytic Methods for the Oil and Gas Extraction Point Source Category,” EPA-821-R-11-004. See § 435.11(ee) and (uu). Table 1—Properties for Reference C 16 -C 18 IOs SBF Used in Discharge Sediment Toxicity Testing Mud weight of SBF discharged with cuttings (pounds per gallon) Reference C 16 -C 18 IOs SBF (pounds per gallon) Reference C 16 -C 18 IOs SBF synthetic to water ratio (%) 8.5-11 9.0 75/25 >11-14 11.5 80/20 >14 14.5 85/15 Plastic Viscosity (PV), centipoise (cP) 12-30 Yield Point (YP), pounds/100 sq. ft 10-20 10-second gel, pounds/100 sq. ft 8-15 10-minute gel, pounds/100 sq. ft 12-30 Electrical stability, V >300 [66 FR 6901, Jan. 22, 2001, as amended at 77 FR 29845, May 18, 2012]