Texas Railroad Commission rules integrity tests for intrastate pipelines
The Texas Railroad Commission Tuesday unanimously adopted its first rule for integrity testing 150,000 miles of intrastate pipelines already in place for transportation of natural gas and hydrocarbon liquids.
HOUSTON, Apr. 10 -- The Texas Railroad Commission Tuesday unanimously adopted its first rule for integrity testing of 150,000 miles of intrastate pipelines already in place for transportation of natural gas and hydrocarbon liquids.
The state regulatory agency already had rules for the manufacture of pipe and installation of pipelines, but nothing that previously required periodic testing of those pipelines after they were installed, officials said.
The new regulation was prompted in part by the Aug. 19 rupture of a natural gas pipeline near Carlsbad, NM, that killed 12 people, and by a recent US Department of Transportation rule for integrity testing of interstate liquids pipelines, said commission staffers.
The move makes Texas one of only two states now requiring integrity testing of pipelines, official said. California, the other state, calls for operators to do hydrostatic tests of liquids pipelines every 5 years.
However, the new Texas rule extends to a greater amount of pipeline and applies its �more stringent requirements more broadly to include all intrastate pipelines,� said Texas Railroad Commission Chairman Tony Garza.
The Texas rule applies to intrastate natural gas transmission lines, hazardous liquids lines and jurisdictional gathering lines, staffers said. Operators have a year either to select a prescriptive testing program outlined by the commission, develop their own risk-based inspection plans, or adopt a combination of the two measures.
The prescriptive plan stipulates either internal inspection or pressure tests. It requires initial testing to be completed before 2006 or by 2011, depending upon how frequently testing is required based on pipe size, pressure, location, proximity to urban areas or water-crossings, and type of product transported.
The inspection interval is 10 years for gas transmission and gathering lines with diameters of 8 in. or less and that operate at pressures greater than 100 psi, with less than 20% specified maximum yield strength (SMYS). For the same size pipe with an SMYS greater than 20%, the inspection interval drops to 5 years. The 5-year interval also applies to those gas transmission and gathering lines that are larger than 8 in. and that operate with pressures greater than 100 psi.
In rural areas, pipelines transporting crude, refined products, or carbon dioxide are subject to 10-year inspection intervals.
But inspections are required every 5 years for those lines when they are in urban areas or cross navigable waterways. The 5-year inspection schedule also applies to crude gathering lines in those same areas as well as to all lines carrying highly volatile liquids, officials said.
Operators opting for a risk-based inspection program must submit their plans to the Texas Railroad Commission by Jan. 1 and update those plans every 36 months, officials said. The frequency of testing is based on the same factors as in the prescriptive plan, as well as other considerations.
The risk-based plans may include internal inspections, using tools capable of detecting pipeline defects; pressure testing for leaks and overall pipe strength; and direct assessment by physical examination of the pipe in specific locations.
Under the risk-based plan, operators must complete at least 50% of initial assessments before 2006 and the rest by 2011.
Any immediate hazards discovered during inspections must be promptly removed, officials said. Other anomalies that can �reasonably be predicted to become hazardous defects� are to be mitigated no later than the next test interval.
Texas Railroad Commission staffers said they know of no calculations as to how much the new inspection program will cost intrastate pipeline operators.
However, they said the Association of Texas Intrastate Natural Gas Pipelines and the Texas Oil and Gas Association did not specifically oppose adoption of the new rule but worked with the commission on specific wording of its requirements.
Contact Sam Fletcher at Samf@OGJonline.com