2 Colo. Code Regs. § 404-1-408

Current through Register Vol. 47, No. 20, October 25, 2024

Section 2 CCR 404-1-408 - GENERAL DRILLING RULES

Unless altered, modified, or changed for a particular Field or formation upon hearing before the Commission the following will apply to the drilling or deepening of all Wells:

a.Closed Loop Drilling. Closed loop drilling is required except where only water-based bentonitic drilling Fluids will be used, the wellbore will not penetrate salt-bearing formations, the Pit will not be in contact with shallow Groundwater, and the Pit will not be located within 2,000 feet of any Building Unit, a lined drilling Pit system may be used.

b.Bottom Hole Location. Unless authorized by the provisions of Rule 410, Operators will drill all Wells so that the horizontal distance between the bottom of the hole and the location at the top of the hole will be at all times a practical minimum.

c.Requirement to Post Permit at the Rig. The Operator will post a copy of the approved Form 2 in a conspicuous place on the drilling rig or workover rig.

d.Requirement to Provide Spud Notice.An Operator will provide advance notice to the Director on a Form 42 - Notice of Spud, no less than 2 business days prior to spudding a Well.

e.Drilling Fluid, Casing, and Cement Program to Isolate Hydrocarbon Formations and Groundwater and for Well Control.

(1) The casing and cementing plan for each Well will prevent migration of oil, gas, and water within Potential Flow Zones from one formation to another behind the casing.

(2) The casing and cementing plan will ensure Groundwater penetrated by the wellbore will be isolated from the infiltration of hydrocarbons or water from other formations penetrated by the wellbore. At a minimum, the Director will require that the Operator's casing and cement plan for a Well will isolate Groundwater with fully-cemented surface casing or a combination of fully-cemented surface casing and stage cement for other casing string(s) across the Groundwater and to a depth 50 feet below the Groundwater and to 50 feet above it or to surface, in formations that meet the following standards:

A. Groundwater that has been classified pursuant to 5 C.C.R. § 1002-41 as Domestic Use - Quality, Agricultural Use - Quality, Surface Water Quality Protection, or Potentially Usable Quality; and

B. Groundwater that has not been classified pursuant to 5 C.C.R. § 1002-41, and with total dissolved solids ("TDS") less than 10,000 mg/l.

C. Only the version of Colorado Department of Public Health and Environment, Water Quality Control Commission ("WQCC"), Regulation Number 41, The Basic Standards for Ground Water, 5 C.C.R. § 1002-41, et seq. in effect as of January 15, 2021 applies to this Rule 408.e; later versions do not apply. A copy of 5 C.C.R. § 1002-41 is available for public inspection during normal business hours from the Public Room Administrator at the office of the Commission, 1120 Lincoln Street, Suite 801, Denver, Colorado 80203. In addition, 5 C.C.R. § 1002-41 may be examined at the Colorado Department of Public Health and Environment, 4300 Cherry Creek Drive South, Denver, CO 80246, and is available at https://www.colorado.gov/pacific/cdphe/water-quality-control-commission-regulations.

(3)Surface Casing Where Subsurface Conditions Are Unknown. In areas where pressure and formations are unknown, surface casing will be run for Well control to reach a depth approved by the Director that is a minimum depth of 10% of true vertical depth ("TVD") of the deepest point of the planned Well (or as required by Commission order) and will be of sufficient size to permit the use of an intermediate string or strings of casings. Surface casing will be set in or through an impervious formation and will be cemented by pump and plug or displacement or other approved method with sufficient cement to fill the Annulus to the top of the hole, all pursuant to reasonable requirements of the Director.

(4)Surface Casing Where Subsurface Conditions Are Known. For Wells drilled in areas where subsurface conditions have been established by drilling experience, surface casing, sized at the Operator's option, will be set and cemented to the surface by the pump and plug or displacement or other approved method at a depth approved by the Director, and for Well control, to a minimum depth of 10% of TVD of the deepest point of the planned Well (or as required by Commission order).

(5)Alternate Isolation by Stage Cementing.

A. In areas where Groundwater is of such depth as to make it impractical to set the full amount of surface casing necessary to comply fully with the requirement to isolate Groundwater, the Director may approve isolation by stage cementing behind the intermediate and/or production casing so as to accomplish the required result.

B. If either the top or bottom depths, or the concentration of TDS in identified Groundwater are uncertain or unknown based on available sources of pertinent information as described in Rule 308.b.(6):

i. The Operator will collect site-specific data sufficient to ensure compliance with all casing and cementing requirements of this Rule 408.e, and submit that information in its casing and cementing plan or in an amended plan that is approved by the Director before the Operator completes the Well; or

ii. The Operator's casing and cementing plan will provide for extending surface casing or cementing behind intermediate and/or production casing to isolate all Groundwater where TDS concentrations are uncertain or unknown. To isolate Groundwater, where the top or bottom depth of Groundwater is unknown or uncertain the Operator's casing and cementing plan will provide for:

aa. Extending surface casing and cement from the surface to 50 feet below the lowest bottom depth;

bb. Stage cementing behind intermediate and/or production casing to 50 feet above the highest top or 50 feet below the lowest bottom depth; or

cc. Extending primary production cement from the bottom of the casing to 50 feet above the highest top that is not otherwise isolated by surface casing and cement or alternate stage cement and casing string.

C. If Groundwater not identified in the casing and cementing plan is encountered after setting the surface casing with either (a) a TDS concentration less than 10,000 mg/l, or (b) unknown or uncertain TDS concentration, the Operator will isolate the Groundwater by stage cementing the intermediate and/or production casing with a solid cement plug extending from 50 feet below the Groundwater to 50 feet above the Groundwater, with the Director's approval. In such cases the Operator will submit an amended casing and cementing plan reflecting the Groundwater and stage cementing within 20 days.

(6) All hole intervals drilled prior to reaching the base of the surface casing or as required by permit condition will be drilled with air, fresh water, or a fresh water-based bentonitic drilling mud. Any other additives will be reviewed and approved by the Director prior to use.

(7) All casing cemented in a Well will be steel casing.

(8) Prior to placing casing in the hole, the Operator will ensure the casing has been tested to verify integrity. An Operator may:

A. For new pipe only, use the mill test pressure;

B. Hydrostatically pressure test the casing with an applied pressure at least equal to the maximum pressure to which the pipe will be subjected in the Well; or

C. Use a casing evaluation tool.

(9) Prior written approval from the Director on a Form 4 is required before commencing any of the following operations:

A. Pumping cement down the Bradenhead access to the Annulus between the production casing (or intermediate casing, if present) and surface casing;

B. All routine or planned casing repair operations; or

C. Any other changes to the casing or cement in the wellbore.

(10) In the case of unforeseen casing repairs during Well operations, the Operator will obtain oral approval from the Director, and will immediately submit a Form 4 confirming the repairs and approval.

(11) An Operator will submit a Form 5, Drilling Completion Report, within 30 days of the completion of the operations listed above, pursuant to Rule 414.b.(3).

(12) Prior written approval from the Director on a Form 4 is required before changing the gross interval of perforations in a completed formation, including into a formation designated as a common source of supply. A Form 5A, Completed Interval Report, will be submitted within 30 days of the gross interval change, pursuant to Rule 416.

f.Cementing.

(1) Operators will use the pump and plug method. An Operator will use a top plug to reduce contamination of cement from the displacement of fluid. An Operator will use a bottom plug or other Director-approved isolation technique or equipment to reduce contamination from drilling mud within the casing.

(2) Unless the Director approves otherwise,

A. The diameter of the drilled hole in which surface casing will be set and cemented will be at least 1.5 inches greater than the nominal outside diameter of the casing the Operator will install; and

B. All other casing will be set and cemented with at least 0.84 inches between the nominal outside diameter of the casing being cemented and the previously set casing's inside nominal diameter.

(3) The Operator will design and place cement in a manner that inhibits channeling of the cement in the annular space outside of the casing being cemented. During placement of cement, the Operator will monitor pump rates to verify the rates remain within design parameters and ensure displacement meets the design. The Operator will monitor the cementing process to ensure proper cement densities are maintained.

(4) When cement is required, the Operator will use a cement slurry that isolates all Groundwater, hydrocarbon, corrosive, Potential Flow, or hydrogen sulfide zones.

(5) The Operator will prepare cement slurry to:

A. The designed density;

B. Minimize free fluid content, to the extent practicable;

C. Ensure cement slurry free water separation will not exceed 3 milliliters per 250 milliliters of cement; and

D. Ensure the cement mix water chemistry is appropriate for the cement slurry design.

(6) The Operator or cement services provider will test a cement mixture at a rate that is the most frequent of every 6 months or when there is a change in operating conditions, cement type, or cement vendor.

A. The test will be on representative samples of the cement and additives.

B. The Operator will make cement test data available to the Director upon request.

g.Casing Centralization.

(1)Surface casing. At a minimum, the Operator will centralize casing as follows:

A. Within 120 feet of the of the surface;

B. At the casing shoe;

C. Above and below a stage collar or diverting tool, if run; and

D. Every fourth joint.

E. The Operator may implement an alternative centralization plan for surface casing if approved by the Director.

(2)Production and Intermediate Casing. The Operator will provide adequate centralization or other methods to achieve cementing objectives in accordance with the permitted Well design.

h.Wellbore Circulation. Prior to cementing, the Operator will clean and condition the wellbore to control gas flow, foster adequate cement displacement, and ensure a bond between cement, casing, and the wellbore.

i.Surface and Intermediate Casing Cementing.

(1) The Operator will ensure that all surface and intermediate casing cement required under this Rule 405.i achieves a minimum compressive strength of 300 psi after 24 hours and 800 psi after 72 hours measured at 800 psi confining pressure and 95° Fahrenheit or at the minimum expected downhole temperature.

(2) The Operator will cement all surface casing with a continuous column from the bottom of the casing to the surface.

(3) After thorough circulation of the wellbore as required by Rule 408.h, the Operator will pump cement behind the intermediate casing to at least 500 feet above the top of the shallowest known production horizon and as required in Rule 408. The Operator will allow cement placed behind the surface and intermediate casing to set a minimum of 8 hours or until 300 psi calculated compressive strength is developed, whichever occurs first, prior to commencing drilling operations. If the surface casing cement level falls below the surface or if there is evidence of inadequate cement coverage, the Operator will consult with the Director and, upon request, provide and implement a corrective action plan prior to drilling ahead.

j.Production Casing Cementing.

(1) The Operator will ensure that all cement required under this Rule 408 placed behind production casing achieves a minimum compressive strength of at least 300 psi after 24 hours and of at least 800 psi after 72 hours both measured at 800 psi at either 95° Fahrenheit or at the minimum expected downhole temperature.

(2) After thorough circulation of a wellbore as required by Rule 408.h, the Operator will pump cement behind the production casing to the shallower of: 500 feet above the top of the shallowest uncovered known producing horizon, isolation of specific geologic intervals specified in the permit, or isolation of any other zone as required by Rule 408.e.

k.Surface Casing Pressure Testing.

(1) Prior to drilling out below the surface casing shoe, the Operator will successfully pressure test the surface casing for a minimum 30 minute duration and to a minimum of 1,500 psi or to a pressure that will determine if the casing has adequate mechanical integrity to meet the Well design and construction objectives.

(2) If the surface casing is exposed to more than 360 rotating hours after reaching total depth or the depth of the next casing string, the Operator will verify the integrity of the surface casing before running the next casing string by using a casing evaluation tool, conducting a mechanical integrity test, or using an equivalent casing evaluation method submitted to and approved by the Director through a Form 4.

l.Intermediate Casing Pressure Testing.

(1) Prior to drilling out below the intermediate casing shoe, the Operator will successfully pressure test the intermediate casing to ensure integrity is adequate to meet Well design and construction objectives. The Operator will perform the pressure test for a minimum 30-minute duration and to a minimum of 1,500 psi unless otherwise approved by the Director.

(2) The Operator will monitor the Well's Bradenhead pressure during any pressure test conducted pursuant to Rule 408.l.

m.Production Casing and Stimulation String Pressure Testing.

(1) Prior to Stimulation, the Operator will successfully pressure test the production casing or Stimulation string, if used. The Operator will pressure test from the wellhead to a minimum depth of 200 feet above the TVD of the top perforations.

(2) For production casing that will be exposed to Stimulation and the Stimulation string, the Operator will perform the pressure test for a minimum of 30 minutes and to a minimum of 500 psi greater than the maximum surface pressure anticipated to be imposed during the Stimulation.

(3) For Wells that are not Stimulated and production casing that will not be exposed to the Stimulation, the Operator will perform the pressure test for a minimum of 30 minutes and to a minimum of 500 psi greater than the maximum anticipated surface pressure.

(4) The Operator will monitor the Well's Bradenhead pressure during any pressure test conducted pursuant to Rule 408.m.

n.Casing Pressure Test Monitoring and Success Criteria for All Casing Strings.

(1) An Operator has successfully conducted a pressure test when:

A. The surface pressure does not change more than 5% from the initial test pressure;

B. The pressure does not change more than 1% during the last 5 minutes of the test; and

C. The Bradenhead pressure does not change more than 5% during the test when testing the intermediate or production casings.

(2) In the event of an indication that a Well no longer has mechanical integrity, the Operator may not conduct stimulation on any Well on the Oil and Gas Location until the Operator has determined the Well has mechanical integrity. If a Well intervention is necessary, the Operator will obtain verbal approval from the Director for the intervention and authorization to proceed with the Stimulation.

o.Isolation When Drilling Operations Are Suspended Before Running Production Casing. In the event drilling operations are suspended before production casing is run, the Operator will notify the Director immediately and will take adequate and proper precautions to prevent migration of oil, gas, and water between formations in the open hole until drilling resumes or the Well is Plugged and Abandoned.

p.Protection of Productive Strata During Deepening Operations. If a Well is deepened for the purpose of producing oil and gas from a lower stratum, such deepening to and completion in the lower stratum will be conducted in such a manner as to protect all upper productive strata.

q.Requirement to Evaluate Disposal Zones for Hydrocarbon Potential. If a Well is drilled as a disposal Well then the Injection Zone will be evaluated for hydrocarbon potential. The proposed hydrocarbon evaluation method will be submitted in writing and approved by the Director prior to implementation. The productivity results will be submitted to the Director upon completion of the Well.

r.Requirement to Log Well. For all new drilling operations, the Operator will run a minimum of a resistivity Log with gamma-ray or other petrophysical Log(s) approved by the Director that adequately describe the stratigraphy of the wellbore. A cement bond Log, capable of generating a variable density display, will be run on all production casing or, in the case of a production liner, the intermediate casing, when these casing strings are run. The Operator will submit these Logs and all other Logs run with the Form 5. The Operator will run open-hole Logs or equivalent cased-hole Logs at depths that adequately verify the setting depth of surface casing and any Groundwater coverage. These requirements will not apply to unlogged open-hole completion intervals.

s.Remedial Cementing. If cement coverage in any casing string does not satisfy the requirements of Rule 408.e, the Director may apply a condition of approval for Form 2 to require remedial cementing and a cement bond log or other cement evaluation tool before recompletion, reentering, or deepening operations consistent with the provisions for isolating Groundwater and hydrocarbon bearing zones in this Rule 408.

t.Statewide Wellbore Collision Prevention. An Operator will perform an anti-collision evaluation of all active (producing, shut in, or temporarily abandoned) offset wellbores that have the potential of being within 150 feet of a proposed Well prior to drilling operations for the proposed Well. The Operator will give notice to all offset Operators prior to drilling.

u.Statewide Setback for Hydraulic Fracturing Treatment.

(1) No portion of a proposed wellbore that will be treated by hydraulic fracturing may be located within 150 feet of an existing (producing, shut-in, or temporarily abandoned) or permitted interval of an oil and gas wellbore that has been or will be treated by hydraulic fracturing belonging to another Operator without the signed written consent of the Operator of the encroached upon wellbore. The Operator will attach any signed written consents to the Form 2 for the proposed wellbore.

(2) The Operator will measure the distance between the proposed and offset wellbores using the directional survey for drilled wellbores and the deviated drilling plan for permitted wellbores, or as otherwise reflected in the Commission's Well records. The Operator will measure the distance from the perforation or mechanical isolation device.

v.Notice Prior to Hydraulic Fracturing Treatment. At least 90 days prior to the anticipated commencement of Hydraulic Fracturing Treatment, the Operator of the wellbore that will be stimulated by Hydraulic Fracturing Treatment will provide notice of Hydraulic Fracturing Treatment commencement to all Operators of offset Wells that were identified pursuant Rule 308.b.(7).A.

w.Offset Wellheads and Surface Equipment. Prior to Hydraulic Fracturing Treatments, the Operator will ensure offset existing Wells within 1,500 feet of the wellbore to be hydraulically fractured that are producing, shut-in, or temporarily abandoned have surface equipment (wellhead and master valve) rated to a pressure adequate to contain anticipated surface pressures that could occur from the proposed Hydraulic Fracturing Treatment. For offset Wells that do not have adequately rated surface equipment, the Operator may instead use downhole mechanical isolation above perforations in the objective formation to prevent unanticipated migration of pressure.

x.Consent to Offset Well Mitigation. When an offset Well and a proposed Well are under different operatorship, the Operator of the offset Well will not refuse to have the offset Well appropriately mitigated to meet the requirements of the Commission's Rules necessary to ensure protection of and minimize adverse impacts to public health, safety, welfare, the environment, and wildlife resources.

y.Communication Prevention. An Operator will take all necessary measures to prevent communication along any known conduits between a wellbore's hydraulic fracturing-treated interval and Groundwater.

z.Surface Equipment Used in Hydraulic Fracturing Treatment. Prior to beginning a Hydraulic Fracturing Treatment, the Operator will rig up and pressure test any surface equipment exposed to Hydraulic Fracturing Treatment pressure. The Operator will test for the proposed Hydraulic Fracturing Treatment design and, at a minimum, to 110% of the maximum anticipated surface Hydraulic Fracturing Treatment pressure. The test will ensure an appropriate safety factor and prevent Fluid losses.

aa.Hydraulic Fracturing Treatment Monitoring. The Operator will monitor and record Hydraulic Fracturing Treatment parameters including but not limited to the following list:

(1) Surface injection pressure (psig);

(2) Slurry rate (bpm);

(3) Proppant concentration (ppg);

(4) Fluid rate (bpm);

(5) Identities, rates, and concentrations of additives used; and

(6) All other annuli pressures or volumes measured at the surface.

2 CCR 404-1-408

37 CR 16, August 25, 2014, effective 9/30/2014

38 CR 01, January 10, 2015, effective 2/14/2015

38 CR 03, February 10, 2015, effective 3/2/2015

38 CR 07, April 10, 2015, effective 4/30/2015

38 CR 16, August 25, 2015, effective 9/14/2015

39 CR 04, February 25, 2016, effective 3/16/2016

41 CR 05, March 10, 2018, effective 4/1/2018

41 CR 06, March 25, 2018, effective 5/1/2018

41 CR 23, December 10, 2018, effective 12/30/2018

42 CR 02, January 25, 2019, effective 2/14/2019

42 CR 17, September 10, 2019, effective 9/30/2019

42 CR 24, December 25, 2019, effective 1/14/2020

43 CR 17, September 10, 2020, effective 9/30/2020

43 CR 13, July 10, 2020, effective 11/2/2020

43 CR 24, December 25, 2020, effective 1/15/2021

45 CR 07, April 10, 2022, effective 4/30/2022

45 CR 09, May 10, 2022, effective 5/30/2022

45 CR 13, July 10, 2022, effective 7/30/2022