8.	Commitments and Contingencies

At December 31, 2017, we had outstanding employment agreements with all four of our executive officers that contained automatic renewal provisions providing that such agreements may be automatically renewed for successive terms of one year unless the employment is terminated at the end of the term by written notice given to the employee not less than 60 days prior to the end of such term. Our maximum commitment under the employment agreements, which would apply if the employees covered by these agreements were each terminated without cause, resigned for good reason, or received a notice of non-renewal was approximately $6.3 million at December 31, 2017. This estimate assumes the maximum potential bonus for 2017 is earned by each executive officer during 2017.

In 2016, we recorded a contractual settlement of $1.4 million, which is recorded in other income on our consolidated statements of operations.

We lease our office space in Fort Worth, Texas, under a non-cancelable agreement that expires on September 30, 2021. We also have non-cancelable operating lease commitments related to office equipment that expire by 2022. The following is a schedule by years of future minimum rental payments required under our operating lease arrangements as of December 31, 2017 (in thousands):

2018	$	852
2019		861
2020		875
2021		673
2022		4
Total	$	3,265

Rent expense under our lease arrangements amounted to $748,000, $1,025,000 and $1,002,000 for the years ended December 31, 2017, 2016 and 2015, respectively.

Litigation

We are involved in various legal and regulatory proceedings arising in the normal course of business. While we cannot predict the outcome of these proceedings with certainty, we do not believe that an adverse result in any pending legal or regulatory proceeding, individually or in the aggregate, would be material to our consolidated financial condition or cash flows.

In 2016, we received $1.1 million from a service provider in a legal settlement, which reduced our current liabilities on our consolidated balance sheets and is recorded as a reduction in additions to oil and gas properties on our consolidated statements of cash flows.

Environmental Issues

We are engaged in oil and gas exploration and production and may become subject to certain liabilities or damages as they relate to environmental clean up of well sites or other environmental restoration or ground water contamination, in connection with drilling or operating oil and gas wells. In connection with our acquisition of existing or previously drilled well bores, we may not be aware of what environmental safeguards were taken at the time such wells were drilled or during such time the wells were operated. Should it be determined that a liability exists with respect to any environmental clean up, restoration or contamination, we would be responsible for curing such a violation or paying damages. No claim has been made, nor are we aware of any liability that exists, as it relates to any environmental clean up, restoration, contamination or the violation of any rules or regulations relating thereto.