Basis of Presentation The accompanying condensed consolidated financial statements of ProPetro Holding Corp. and its subsidiary (the "Company," "we," "us" or "our") have been prepared in accordance with the requirements of the U.S. Securities and Exchange Commission ("SEC") for interim financial information and do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America ("GAAP") for annual financial statements. Those adjustments (which consisted of normal recurring accruals) that are, in the opinion of management, necessary for a fair presentation of the results of the interim periods have been made. Results of operations for such interim periods are not necessarily indicative of the results of operations for a full year due to changes in market conditions and other factors. The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2018 included in our Form 10-K filed with the SEC ("Form 10-K"). Revenue Recognition The Companys services are sold based upon contracts with customers. The Company recognizes revenue when it satisfies a performance obligation by transferring control over a product or service to a customer. The following is a description of the principal activities, separated by reportable segment and all other, from which the Company generates its revenue. Pressure Pumping  Pressure pumping consists of downhole pumping services, which includes hydraulic fracturing (inclusive of acidizing services) and cementing. Hydraulic fracturing is a well-stimulation technique intended to optimize hydrocarbon flow paths during the completion phase of shale wellbores. The process involves the injection of water, sand and chemicals under high pressure into shale formations. Our hydraulic fracturing contracts have one performance obligation, contracted total stages, satisfied over time. We recognize revenue over time using a progress output method, unit-of-work performed method, which is based on the agreed fixed transaction price and actual stages completed. We believe that recognizing revenue based on actual stages completed faithfully depicts how our hydraulic fracturing services are transferred to our customers over time. Acidizing, which is part of our hydraulic fracturing operating segment, involves a well-stimulation technique where acid is injected under pressure into formations to form or expand fissures. Our acidizing contracts have one performance obligation, satisfied at a point-in-time upon completion of the contracted service when control is transferred to the customer. Jobs for these services are typically short term in nature, with most jobs completed in less than a day. We recognize acidizing revenue at a point-in-time, upon completion of the performance obligation. Our cementing services use pressure pumping equipment to deliver a slurry of liquid cement that is pumped down a well between the casing and the borehole. Our cementing contracts have one performance obligation, satisfied at a point-in-time upon completion of the contracted service when control is transferred to the customer. Jobs for these services are typically short term in nature, with most jobs completed in less than a day. We recognize cementing revenue at a point-in-time, upon completion of the performance obligation. The transaction price for each performance obligation for all our pressure pumping services are fixed per our contract with our customers. All Other  All other consists of our coil tubing, drilling and flowback, which are all downhole well stimulation and completion/remedial services. The performance obligation for each of the services has a fixed transaction price which is satisfied at a point-in-time upon completion of the service when control is transferred to the customer. Accordingly, we recognize revenue at a point-in-time, upon completion of the service and transfer of control to the customer. Accounts Receivable Accounts receivables are stated at the amount billed and billable to customers. At March 31, 2019 and December 31, 2018 , accrued revenue (unbilled receivable) included as part of our accounts receivable was $33.8 million and $18.0 million , respectively. At March 31, 2019 , the transaction price allocated to the remaining performance obligation for our partially completed hydraulic fracturing operations was $79.8 million , which is expected to be completed and recognized in one month following the current period balance sheet date, in our pressure pumping reportable segment.