Drilling fluid
Drilling fluid means the circulating fluid (mud) used in the rotary drilling of wells to clean and condition the hole and to counterbalance formation pressure. Classes of drilling fluids are:
(1) Water-based drilling fluid means the continuous phase and suspending medium for solids is a water-miscible fluid, regardless of the presence of oil.
(2) Non-aqueous drilling fluid means the continuous phase and suspending medium for solids is a water-immiscible fluid, such as oleaginous materials (e.g., mineral oil, enhanced mineral oil, paraffinic oil, C16–C18 internal olefins, and C8–C16 fatty acid/2-ethylhexyl esters).
(i) Oil-based means the continuous phase of the drilling fluid consists of diesel oil, mineral oil, or some other oil, but contains no synthetic material or enhanced mineral oil.
(ii) Enhanced mineral oil-based means the continuous phase of the drilling fluid is enhanced mineral oil.
(iii) Synthetic-based means the continuous phase of the drilling fluid is a synthetic material or a combination of synthetic materials.
(m) Enhanced mineral oil as applied to enhanced mineral oil-based drilling fluid means a petroleum distillate which has been highly purified and is distinguished from diesel oil and conventional mineral oil in having a lower polycyclic aromatic hydrocarbon (PAH) content. Typically, conventional mineral oils have a PAH content on the order of 0.35 weight percent expressed as phenanthrene, whereas enhanced mineral oils typically have a PAH content of 0.001 or lower weight percent PAH expressed as phenanthrene.
(n) Exploratory facility means any fixed or mobile structure subject to this subpart that is engaged in the drilling of wells to determine the nature of potential hydrocarbon reservoirs.
(o) Formation oil means the oil from a producing formation which is detected in the drilling fluid, as determined by the GC/MS compliance assurance method, EPA Method 1655, when the drilling fluid is analyzed before being shipped offshore, and as determined by the RPE method, EPA Method 1670, when the drilling fluid is analyzed at the offshore point of discharge. The GC/MS compliance assurance method and the RPE method approved for use with this part 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 paragraph (uu) of this section. Detection of formation oil by the RPE method may be confirmed by the GC/MS compliance assurance method, and the results of the GC/MS compliance assurance method shall apply instead of those of the RPE method.
(p) M9IM means those offshore facilities continuously manned by nine (9) or fewer persons or only intermittently manned by any number of persons.
(q) M10 means those offshore facilities continuously manned by ten (10) or more persons.
(r) Maximum as applied to BAT effluent limitations and NSPS for drilling fluids and drill cuttings means the maximum concentration allowed as measured in any single sample of the barite for determination of cadmium and mercury content.
(s) Maximum for any one day as applied to BPT, BCT and BAT effluent limitations and NSPS for oil and grease in produced water means the maximum concentration allowed as measured by the average of four grab samples collected over a 24-hour period that are analyzed separately. Alternatively, for BAT and NSPS the maximum concentration allowed may be determined on the basis of physical composition of the four grab samples prior to a single analysis.
(t) Maximum weighted mass ratio averaged over all NAF well sections for BAT effluent limitations and NSPS for base fluid retained on cuttings means the weighted average base fluid retention for all NAF well sections as determined by EPA Method 1674, which is published as an appendix 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 paragraph (uu) of this section.
(u) Method 1654A refers to EPA Method 1654, Revision A, entitled “PAH Content of Oil by HPLC/UV,” December 1992, which is published as an appendix 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 paragraph (uu) of this section.
(v) Minimum as applied to BAT effluent limitations and NSPS for drilling fluids and drill cuttings means the minimum 96-hour LC5. value allowed as measured in any single sample of the discharged waste stream. Minimum as applied to BPT and BCT effluent limitations and NSPS for sanitary wastes means the minimum concentration value allowed as measured in any single sample of the discharged waste stream.
(w)
(1) New source means any facility or activity of this subcategory that meets the definition of “new source” under 40 CFR 122.2 and meets the criteria for determination of new sources under 40 CFR 122.29(b) applied consistently with all of the following definitions:
(i) Water area as used in “site” in 40 CFR 122.29 and 122.2 means the water area and water body floor beneath any exploratory, development, or production facility where such facility is conducting its exploratory, development or production activities.
(ii) Significant site preparation work as used in 40 CFR 122.29 means the process of surveying, clearing or preparing an area of the water body floor for the purpose of constructing or placing a development or production facility on or over the site.
(2) “New Source” does not include facilities covered by an existing NPDES permit immediately prior to the effective date of these guidelines pending EPA issuance of a new source NPDES permit.
(x) No discharge of free oil means that waste streams may not be discharged that contain free oil as evidenced by the monitoring method specified for that particular stream, e.g., deck drainage or miscellaneous discharges cannot be discharged when they would cause a film or sheen upon or discoloration of the surface of the receiving water; drilling fluids or cuttings may not be discharged when they fail EPA Method 1617 (Static Sheen Test), which is published as an appendix 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 paragraph (uu) of this section.
(y) Parameters that are regulated in this subpart and listed with approved methods of analysis in Table 1B at 40 CFR 136.3 are defined as follows:
(1) Cadmium means total cadmium.
(2) Chlorine means total residual chlorine.
(3) Mercury means total mercury.
(4) Oil and Grease means total recoverable oil and grease.
(z) PAH (as phenanthrene) means polynuclear aromatic hydrocarbons reported as phenanthrene.
(aa) Produced sand means the slurried particles used in hydraulic fracturing, the accumulated formation sands and scales particles generated during production. Produced sand also includes desander discharge from the produced water waste stream, and blowdown of the water phase from the produced water treating system.
(bb) Produced water means the water (brine) brought up from the hydrocarbon-bearing strata during the extraction of oil and gas, and can include formation water, injection water, and any chemicals added downhole or during the oil/water separation process.
(cc) Production facility means any fixed or mobile structure subject to this subpart that is either engaged in well completion or used for active recovery of hydrocarbons from producing formations.
(dd) Sanitary waste means the human body waste discharged from toilets and urinals located within facilities subject to this subpart.
(ee) Sediment toxicity as applied to BAT effluent limitations and NSPS for drilling fluids and drill cuttings refers to EPA Method 1644: “Method for Conducting a Sediment Toxicity Test with Leptocheirus plumulosus and Non-Aqueous Drilling Fluids or Synthetic-Based Drilling Muds” and sediment preparation procedures specified in EPA Method 1646. EPA Method 1644 is published in “Analytic Methods for the Oil and Gas Extraction Point Source Category,” (see paragraph (uu) of this section) and EPA Method 1646 is published as an appendix to subpart A of this part.
(ff) Solids control equipment means shale shakers, centrifuges, mud cleaners, and other equipment used to separate drill cuttings and/or stock barite solids from drilling fluid recovered from the wellbore.
(gg) SPP toxicity as applied to BAT effluent limitations and NSPS for drilling fluids and drill cuttings refers to the bioassay test procedure, “Suspended Particulate Phase (SPP) Toxicity Test,” presented in EPA Method 1619, which is published as an appendix 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 paragraph (uu) of this section.
(hh) Static sheen test means the standard test procedure that has been developed for this industrial subcategory for the purpose of demonstrating compliance with the requirement of no discharge of free oil. The methodology for performing the static sheen test is presented in EPA Method 1617, which is published as an appendix 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 paragraph (uu) of this section.
(ii) Stock barite means the barite that was used to formulate a drilling fluid.
(jj) Stock base fluid means the base fluid that was used to formulate a drilling fluid.
(kk) Synthetic material as applied to synthetic-based drilling fluid means material produced by the reaction of specific purified chemical feedstock, as opposed to the traditional base fluids such as diesel and mineral oil which are derived from crude oil solely through physical separation processes. Physical separation processes include fractionation and distillation and/or minor chemical reactions such as cracking and hydro processing. Since they are synthesized by the reaction of purified compounds, synthetic materials suitable for use in drilling fluids are typically free of polycyclic aromatic hydrocarbons (PAH's) but are sometimes found to contain levels of PAH up to 0.001 weight percent PAH expressed as phenanthrene. Internal olefins and vegetable esters are two examples of synthetic materials suitable for use by the oil and gas extraction industry in formulating drilling fluids. Internal olefins are synthesized from the isomerization of purified straight-chain (linear) hydrocarbons such as C16–C18 linear alpha olefins. C16–C18 linear alpha olefins are unsaturated hydrocarbons with the carbon to carbon double bond in the terminal position. Internal olefins are typically formed from heating linear alpha olefins with a catalyst. The feed material for synthetic linear alpha olefins is typically purified ethylene. Vegetable esters are synthesized from the acid-catalyzed esterification of vegetable fatty acids with various alcohols. EPA listed these two branches of synthetic fluid base materials to provide examples, and EPA does not mean to exclude other synthetic materials that are either in current use or may be used in the future. A synthetic-based drilling fluid may include a combination of synthetic materials.
(ll) Well completion fluids means salt solutions, weighted brines, polymers, and various additives used to prevent damage to the well bore during operations which prepare the drilled well for hydrocarbon production.
(mm) Well treatment fluids means any fluid used to restore or improve productivity by chemically or physically altering hydrocarbon-bearing strata after a well has been drilled.
(nn) Workover fluids means salt solutions, weighted brines, polymers, or other specialty additives used in a producing well to allow for maintenance, repair or abandonment procedures.
(oo) 4-day LC5. as applied to the sediment toxicity BAT effluent limitations and NSPS means the concentration (milligrams/kilogram dry sediment) of the drilling fluid in sediment that is lethal to 50 percent of the Leptocheirus plumulosus test organisms exposed to that concentration of the drilling fluids after four days of constant exposure.
(pp) 10-day LC5. as applied to the sediment toxicity BAT effluent limitations and NSPS means the concentration (milligrams/kilogram dry sediment) of the base fluid in sediment that is lethal to 50 percent of the Leptocheirus plumulosus test organisms exposed to that concentration of the base fluids after ten days of constant exposure.
(qq) 96-hour LC5. means the concentration (parts per million) or percent of the suspended particulate phase (SPP) from a sample that is lethal to 50 percent of the test organisms exposed to that concentration of the SPP after 96 hours of constant exposure.
(rr) C16–C18internal olefin means a 65/35 blend, proportioned by mass, of hexadecene and octadecene, respectively. Hexadecene is an unsaturated hydrocarbon with a carbon chain length of 16, an internal double carbon bond, and is represented by the Chemical Abstracts Service (CAS) No. 26952–14–7. Octadecene is an unsaturated hydrocarbon with a carbon chain length of 18, an internal double carbon bond, and is represented by the Chemical Abstracts Service (CAS) No. 27070–58–2. (Properties available from the Chemical Abstracts Service, 2540 Olentangy River Road, PO Box 3012, Columbus, OH, 43210).
(ss) C16-C18internal olefin drilling fluid means a C16-C18 internal olefin drilling fluid formulated as specified in appendix 1 of subpart A of this part.
(tt) C12–C14ester and C8ester means the fatty acid/2-ethylhexyl esters with carbon chain lengths ranging from 8 to 16 and represented by the Chemical Abstracts Service (CAS) No. 135800–37–2. (Properties available from the Chemical Abstracts Service, 2540 Olentangy River Road, PO Box 3012, Columbus, OH, 43210)
(uu) Analytic Methods for the Oil and Gas Extraction Point Source Category is the EPA document, “Analytic Methods for the Oil and Gas Point Source Category,” December 2011, EPA–821–R–11–004, that compiles analytic methods for this category. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be inspected at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202–741–6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. A copy may also be inspected at EPA's Water Docket, 1200 Pennsylvania Ave. NW., Washington, DC 20460. This method may be obtained at http://water.epa.gov/scitech/methods/cwa/index.cfm.