Hydrogen sulfide is produced in association with oil, gas, and water from varying formations throughout the State of Texas; however, there are three major hydrogen sulfide producing areas. The Smackover formation in East Texas, found at depths generally below 12,000 ft, produces hydrogen sulfide in concentrations of less than 1 to 90 percent. In South Central Texas, the Edwards formation, found at depths below 10,000 ft, produces hydrogen sulfide around 2 percent, while in West Texas the shallow San Andres formation produces hydrogen sulfide -in concentrations from 0 to 5 percent. In the remainder of the state, numerous formations produce hydrogen sulfide in varying concentrations.
Drilling and completion of wells in the Smackover formation in the eastern part of the state in 1972 greatly increased the possibility of high volumes of hydrogen sulfide gas escaping to the atmosphere. The combination of the highly toxic gas in densely populated areas was of some concern to our field populated areas was of some concern to our field personnel and based on the recommendations of persons personnel and based on the recommendations of persons employed by the Commission in our Kilgore office, the Commission called a hearing for Feb. 28, 1973, to consider the promulgation of statewide regulation pertaining to production of oil and gas containing pertaining to production of oil and gas containing hydrogen sulfide.
The Texas Mid-Continent Oil and Gas Assn. appeared at this hearing representing the oil industry as a whole and submitted a suggested rule very similar to the one adopted. Representatives of several oil companies pointed out the need for flexibility in any rule adopted and most supported the rule submitted by the Texas Mid-Continent Oil and Gas Assn. As a result of this hearing, Special Order No. 2–62,673 was issued on Sept. 25, 1973, requiring each operator conducting drilling or workover operations or who operated production and gas processing facilities in sour hydrocarbon service to provide adequate safeguards against harm to his employees and to the general public. Sour hydrocarbon service was defined as any operation where the concentration of hydrogen sulfide in the air could exceed 20 ppm. This rule further required drilling and workover operators, as well as operators of production and gas processing facilities, to post appropriate warning signs, to use appropriately designed equipment and materials, and to develop an appropriate contingency plan for emergencies. This order, which was very broad and general, did not require any report by the operators specifying that they were in compliance; however, it did give our district offices authorization to review drilling and production sites for compliance with the sign requirements, with the materials requirement, and with the contingency plan requirement.
Statewide Rule 36 remained in effect with no apparent problems until Feb. 1, 1975, when an undetected escape of gas containing hydrogen sulfide near Denver City, Tex., resulted in the deaths of nine area residents. In order to define more clearly the intentions of the Commission regarding the rule and acting under a legislative mandate, the Commission called a hearing for March 13, 1975, to consider a revision of Statewide Rule 36. Once again the Texas Mid-Continent Oil and Gas Assn. appeared along with representatives of a number of the oil companies. The Texas Mid-Continent Oil and Gas Assn. submitted the following general recommendations for the revision of Statewide Rule 36:
describe materials specification using established and published standards,
require submission of published standards,
require submission of emergency contingency plans to the Commission,
require submission of personal protection programs to the Commission, and
specify fenced and locked facilities that are located in or near populated areas.