Commitments and Contingencies Concentrations of Credit Risk Financial instruments which subject the Company to credit risk consist primarily of cash balances maintained in excess of federal depository insurance limits and trade receivables. Insurance coverage is currently $250,000 per depositor at each financial institution, and the Company's non-interest bearing cash balances exceeded federally insured limits. The Company restricts investment of temporary cash investments to financial institutions with high credit standings. The Companys customer base consists primarily of multi-national and independent oil and natural gas producers. The Company does not require collateral on its trade receivables. For the nine months ended September 30, 2019 , the Company's largest customer, five largest customers, and ten largest customers constituted 9.5% , 34.7% and 45.4% of consolidated revenues, respectively. The loss of any one of the Company's top five customers could have a materially adverse effect on the revenues and profits of the Company. Further, the Company's trade accounts receivable are from companies within the oil and natural gas industry and as such the Company is exposed to normal industry credit risks. As of September 30, 2019 , the Company's largest customer, five largest customers, and ten largest customers constituted 4.0% , 25.4% and 37.1% of accounts receivable, respectively. The Company continually evaluates its reserves for potential credit losses and establishes reserves for such losses. Employee Benefit Plan The Company has a 401(k) retirement plan for substantially all of its employees based on certain eligibility requirements. The Company may provide profit sharing contributions to the plan at the discretion of management. No such discretionary contributions have been made since inception of the plan. Litigation The Company is subject to various other claims and legal actions that arise in the ordinary course of business. The Company does not believe that any of the currently existing claims and actions, separately or in the aggregate, will have a material adverse effect on the Company's business, financial condition, results of operations, or cash flows. It is reasonably possible that cases could be resolved and result in liabilities that exceed the amounts currently reserved; however, we cannot reasonably estimate a range of loss based on the status of the cases. If one or more negative outcomes were to occur relative to these matters, the aggregate impact to the Companys financial condition could be material. Self-Insurance The Company is self-insured under its Employee Group Medical Plan for the first $150 thousand per individual. The Company is self-insured with a retention for the first $250 thousand in general liability. The Company has an additional premium payable clause under its lead $10 million limit excess policy that states in the event a loss exceeds $1 million , a loss additional premium of up to 15% to 17% of paid losses in excess of $1 million will be due. The loss additional premium is payable at the time when the loss is paid and will be payable over a period agreed by insurers. The Company has accrued liabilities totaling $6.3 million and $5.2 million as of September 30, 2019 and December 31, 2018 , respectively, for the projected additional premium and self-insured portion of these insurance claims as of the financial statement dates. This accrual includes claims made as well as an estimate for claims incurred but not reported by using third party data and claims history as of the financial statement dates. Other The Company is currently undergoing sales and use tax audits for multi-year periods. The Company believes the outcome of these audits will not have a material adverse effect on its results of operations or financial position. Because certain of these audits are in a preliminary stage, an estimate of the possible loss or range of loss cannot reasonably be made.