Appendix 8 to Subpart A of Part 435 - Reference C16-C18 Internal Olefin Drilling Fluid Formulation

Appendix 8 to Subpart A of Part 435 - Reference C₁₆-C₁₈ Internal Olefin Drilling Fluid Formulation

The reference C₁₆-C₁₈ 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 LC₅. of C₁₆-C₁₈ internal olefin drilling fluid/4-day LC₅. 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 C₁₆-C₁₈ IOs SBF Used in Discharge Sediment Toxicity Testing

Mud weight of SBF discharged with cuttings (pounds per gallon)	Reference C16-C18 IOs SBF (pounds per gallon)	Reference C16-C18 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]