The Kansas Corporation Commission has started an investigation to determine the cause of a string of strong earthquakes that Hutchinson earlier in August. The largest of the August 16 quakes was 4.2 magnitude, strong enough to be felt by residents in Ponca City, Oklahoma and Kansas City, Missouri.
Windows were broken by the quake in Hutchinson and it brought down ceiling tiles as well in some businesses. The KCC said it has started collecting data and analyzing the recent wastewater injection well activity in Reno County. In announcing the investigation, the state regulators said they would eventually evaluate whether more action is needed to safeguard Kansans.
In 2015, the KCC issued an order reducing injection rates in portions of Harper and Sumner counties after the number of earthquakes in that area began to trend upward. In 2016, the Commission issued a second order limiting injection in additional areas of Harper and Sumner as well as parts of Kingman, Sedgwick and Barber counties when earthquake activity there started to rise.
The area currently under study in Reno County focuses primarily on Arbuckle Formation depth wells and involves both Class ll oil and gas industry injection wells regulated by the KCC and Class l wells regulated by the Kansas Department of Health and Environment (KDHE).
Class ll wells are used to inject fluids associated with oil and natural gas production into deep confined rock formations. There are two types of Class ll injection wells: disposal wells and secondary/enhanced recovery injection wells. Disposal wells are used to inject produced fluids into rock formations that do not produce oil or gas. Typically, the injection formations are isolated from usable quality groundwater and are sealed above and below by cementing steel casing into the unbroken and impermeable well bore and rock formations within the well.
Secondary/enhanced recovery injection wells are used to inject produced fluids back into formations/reservoirs that contain oil or gas. These formations are also isolated from usable quality groundwater. The injection of produced fluid back into potentially productive formations often allows for the increased recovery of oil or gas reserves.
Class l wells are used to inject hazardous and non-hazardous industrial and municipal wastewater into deep, confined rock formations. Disposal typically occurs thousands of feet below the lower most underground source of drinking water (USDW). Industries that utilize Class I wells include: refining, metal production, chemical manufacturing, pharmaceutical industry, commercial disposal, food production and municipal wastewater treatment. Nearly all Class I disposal wells in Kansas inject into the Arbuckle Formation.
To fully evaluate all injection activity in Reno County, the KCC staff is working with other state agencies to collect information regarding well construction, depths, injection volumes, pressures, maintenance practices and any new injection well activity in the area. This investigation and evaluation process is ongoing and dependent upon the complexity of the evolving fact finding process. Accordingly, a precise timeline for completing the investigation has not yet been determined.