055-3 Wyo. Code R. § 3-22 - General Drilling Rules

(a) The following shall apply to the drilling of all wells unless altered, modified, or changed for a particular well, pool, unit, area or lands upon hearing before the Commission:

(i) Surface casing shall be run to reach a depth below all known or reasonably estimated utilizable groundwater (as defined in Chapter 3, Section 8(c)(iv)) to protect the Use Class category and to prevent blowouts or uncontrolled flows. Unless otherwise approved by the Supervisor, surface casing shall be set at a minimum of three (3) joints or approximately one hundred (100) to one hundred twenty (120) feet below the depth of any Wyoming Office of State Engineer permitted water supply wells designated for domestic, stock water, irrigation or municipal use, within a minimum of one-quarter (1/4) mile radius and shall be cemented to surface. Any coalbed methane well receiving a Ground Water Appropriate Permit (Form UW 5) from the State Engineer's Office is exempt from this specific subsection. Fresh water flows detected during drilling, including seismic, core, or other exploratory holes, shall be recorded on Form 19 (Report of Fresh Water Flows) and reported to the Commission on the next business day. Information contained on the form shall describe the depth at which the sand was encountered, the thickness, and the rate of water flow, if known. In areas where pressures and formations are unknown, surface casing shall be of sufficient size to permit the use of an intermediate string or strings of casing. Surface casing shall be set in or through an impervious formation and shall be cemented by the pump and plug or displacement or other approved method with sufficient cement to fill the annulus to the top of the hole, all in accordance with reasonable requirements of the Supervisor. The Supervisor may require the Owner or Operator to pump a specified quantity of excess cement above the design volume if severe washed out hole conditions are known to exist on the surface hole portion of wells in the immediate vicinity of the well to be drilled. If cement is not circulated to the surface during the primary operation, the Owner/Operator shall perform supplemental cementing operations to assure that the annular space from the casing shoe to the surface is filled with cement. The Supervisor may require the Owner or Operator to provide cased hole bond logs to be run for casing strings to demonstrate isolation from the placement of cement across and above the productive intervals or above the last casing shoe in the well, if there is a demonstrated reason to believe an inadequate cement job was performed.

(ii) Unless otherwise provided by specific order of the Commission for a particular well or wells or for a particular pool or parts thereof, cemented casing string shall stand under pressure until the cement at the shoe has reached a compressive strength of five hundred pounds per square inch (500 lbs./sq. in.). In addition, the API free-water separation for all cement slurries used shall average no more than four (4) milliliters per two hundred fifty (250) milliliters of cement. All cements used shall achieve a minimum compressive strength of one hundred (100) psi in twenty-four (24) hours measured at eighty degrees Fahrenheit (80? F.). Testing for these properties shall be in accordance with accepted industry standards. The term "under pressure" as used herein shall be complied with if one float valve is used or if pressure is otherwise held;

(iii) There shall be installed and maintained on all wells blowout preventers and related equipment in accordance with Chapter 3, Section 23(i) of these rules;

(iv) Setting depths of all casing strings shall be determined by taking into account formation fracture gradients and the maximum anticipated pressure to be maintained within the wellbore;

(v) If and when it becomes necessary to run a production string, such string shall be cemented by the pump and plug method and shall be properly tested by the pressure method before cement plugs are drilled;

(vi) Natural gas, which may be encountered in a substantial quantity in any section of cable tool drilled hole above the ultimate objective, shall be shut off with reasonable diligence either by mudding, by casing, or other approved method, and confined to its original source to the satisfaction of the Supervisor. Any gas escaping from the well during drilling operations shall be, so far as practicable, conducted to a safe distance from the well site and burned.

(b) Before drilling commences, approval to construct proper and adequate reserve pits for the reception and confinement of mud and cuttings and to facilitate the drilling operation shall be applied for and received in accordance with Chapter 4, Section 1 of these rules. Special precautions including, but not limited to, an impermeable liner and/or membrane, monitoring systems, or closed systems, shall be taken, if necessary, to prevent contamination of streams and potable water and to provide additional protection to human health and safety in instances where drilling operations are conducted in close proximity to water supplies. Wells, pits, wellheads, pumping units, tanks, and treaters shall be located no closer than three hundred fifty feet (350') from any water supply. The Supervisor may grant a variance to increase or decrease this distance for good cause.

(c) Before drilling commences, the Owner/Operator shall notify the Commission of his intent to spud the well and an approximate time the BOP test will be run.

(d) For each well drilled within the Special Sodium Drilling Area - A or - B (SSDA - A or - B), as defined in Chapter 1, Section 2(ww) and (xx) of these rules, a complete proposed casing and cementing program shall be submitted on the Application for Permit to Drill (Form 1). For the life of the well each drilling and casing program, unless altered, modified, or changed for a particular well, pool, unit, area or lands upon hearing before the Commission, shall be designed to:

(i) Provide suitable and safe operating conditions for the total measured depth proposed;

(ii) Confine fluids to the wellbore;

(iii) Prevent migration of fluids from one stratum to another;

(iv) Assure control of well pressures encountered;

(v) Prevent contamination of freshwater;

(vi) Prevent significant damage to Trona Mineral Resources; and,

(vii) Provide well control until the next casing is set.

All pertinent factors for well control should be considered, including formation fracture gradients, formation pressures, casing setting depths, proposed total depth, and projected mining.

(e) In addition, the following requirements apply to all wells drilled within the Special Sodium Drilling Area - A (SSDA - A), as defined in Chapter 1, Section 2(ww) of these rules, unless altered, modified, or changed for a particular well, pool, unit, area or lands upon hearing before the Commission:

(i) Any oil or gas wells that will be drilled within the area of influence of underground trona mining shall be:

(A) Designed and installed to withstand the forces and potentially damaging influences from mining as certified by a Registered Professional Engineer registered in the state of Wyoming or

(B) Demonstrated to be located outside the mining influence area. Mining influence includes surface subsidence and underground formation collapse, faulting fracturing and related stresses that may provide avenues for communication with active or inactive underground mine works, open mine voids, and corrosive mine fluids that may cause well casing corrosion or failure as a result of mining.

(ii) Conductor casing must be set to a depth of at least forty feet (40') or into a competent stratum, whichever is greater. The casing must be cemented with a quantity of cement to fill the annular space up to the surface and topped off if not at the surface. Cement fill must be verified by observation of cement returns.

(iii) Centralized surface casing shall be set below the Trona Interval from the surface. Centralizers shall be spaced to ensure enough casing annulus is maintained on all sides of the casing to allow cement fill space throughout the cased interval. The casing shall be set into a competent stratum and cemented with sufficient cement in the annulus to circulate to the surface. If cement does not circulate to the surface, the open annulus must be cemented to the surface before drilling ahead. A cement bond log or cement evaluation tool must be run to verify adequate cement around surface casing. Remedial cementing may be required if it is determined that insufficient bonding occurred.

(iv) Prior to well completion, a directional survey shall be run from the base of the Trona Interval to surface to verify wellbore location relative to surface location. Results of the survey shall be submitted to the Supervisor pursuant to Chapter 3, Section 21 of these rules.

(v) Intermediate and/or production casings, if required to be cemented, shall be cemented with a sufficient quantity of cement to provide annular fill up from the surface casing shoe to two hundred feet (200') above the Trona Interval. All casing annuluses reaching the production zones shall be cemented for two hundred feet (200') or more above the highest producing zone. All casings shall be centralized throughout their cemented annulus intervals. Before drilling ahead, all casings shall be tested in accordance with subsection (e)(vii) of this section.

(vi) Liners may be set and cemented as an extension of casings provided that the cemented liner has a minimum of two hundred feet (200') of cemented lap within the next larger casing. Before drilling ahead, a cemented liner and lap must test in accordance with subsection (e)(vii) of this section, to determine that a seal between the liner top and next larger casing has been achieved.

(vii) Before drilling out the liner after cementing, all casing, liners, and liner laps must be tested to a surface pressure of one thousand five hundred (1,500) psig, or 0.25 psi/ft multiplied by the true vertical depth of the casing shoe, whichever is greater; however, surface pressure must not subject the casing to a hoop stress that will exceed seventy percent (70%) of the minimum yield strength of the casing. Sufficient notice of pressure test must be given, so that a representative of the Commission may witness the test. A cement bond log or other appropriate log shall be obtained to evaluate cement integrity in each cemented zone for each cemented casing annulus and the results submitted to the Supervisor for approval, pursuant to Chapter 3, Section 21 of these rules. If there are indications of improper cementing, or the pressure declines more than ten percent (10%) in 30 minutes, corrective measures shall be taken.

(viii) Casing annuluses not cemented through the Trona Interval that extend to the surface shall be continually monitored for leaks by equipping the surface termination with a rupture disk (fail open) pressure relief valve with tattle-tale (or similar device) to detect, alarm, and relieve excess annular pressure buildup. The device shall be set to fail open at one hundred (100) psi. Blocking of this pressure relief valve in an open position shall be prohibited. In the event the monitored casing pressure exceeds one hundred (100) psi, the Supervisor and the trona producers holding valid Wyoming DEQ permits to mine trona shall be notified as soon as possible and remedial actions shall be implemented with the Supervisor's approval. The pressure relief device shall be tested every two (2) years to insure it is functioning properly. Tattle-tale monitoring units that cease to monitor or communicate shall be promptly repaired. Pressure devices shall be repaired or replaced immediately upon failing a pressure test or following a rupture.

(ix) If a well has not been tested for mechanical integrity within five (5) years and is shut-in for an extended period the casing strings capable of being tested shall be evaluated for mechanical integrity during the shut-in period.

(x) Cathodic protection or other equivalent corrosion prevention shall be applied to all casing strings.

(f) Within the Special Sodium Drilling Area - A or - B, as defined in Chapter 1, Section 2(ww) or (xx) of these rules, or all wells defined in Chapter 1, Section 2 of these rules unless altered, modified, or changed upon hearing before the Commission, or shown to contain no Trona Mineral Resources, shall only use stimulation methods that do not significantly damage the Trona Mineral Resources. A plan of work for any stimulation operation shall be submitted to the Supervisor and approved before the work is undertaken.

(i) Well stimulation operations within the Trona Interval shall include a post stimulation survey that identifies the extent of induced fractures. Results of the survey shall be submitted to the Supervisor for evaluation to determine if induced fractures have significantly intersected the Trona Mineral Resources and if corrective action is required.

(ii) Stimulation fluids shall be designed to prevent significant dissolution to the Trona Mineral Resources. The Supervisor shall require corrective action if it is determined that significant damage to the Trona Mineral Resources has, or is likely to occur.

(g) Within the boundaries of the Special Sodium Drilling Area - A or - B, as defined in Chapter 1, Section 2(ww) or (xx) of these rules, all wells defined in Chapter 1, Section 2 of these rules unless altered, modified, or changed upon hearing before the Commission, shall use drilling fluids that will not significantly dissolve the Trona Mineral Resource.

Notes

055-3 Wyo. Code R. § 3-22

Amended, Eff. 6/3/2015. Amended, Eff. 1/19/2016. Amended, Eff. 4/1/2016. Amended, Eff. 12/20/2019. Amended, Eff. 12/9/2020. Amended, Eff. 6/22/2022.