Oklahoma regulators develop new earthquake guidelines

Oklahoma regulators say the number of earthquakes could increase as oil and gas production expands in a broad area of the state, and they're telling energy companies that they need to be ready to shut down if a temblor exceeds magnitude 3.5.

The Oklahoma Corporation Commission on Tuesday released new guidelines to help producers deal with the risks of earthquakes linked to oil and natural gas production in parts of the state.

The panel said the South Central Oklahoma Oil Province and the Sooner Trend Anadarko Basin Canadian and Kingfisher counties fields are expected to account for most new oil and gas activity in Oklahoma. Regulators said the new operations shouldn't produce as much wastewater as in other regions where earthquakes of magnitude 5 or stronger have occurred.