REVENUE FROM CONTRACTS WITH CUSTOMERS

Performance Obligations. Revenue is generally recognized when we transfer control of our products or services to our customers. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring products or providing services to our customers.

Product Sales. Product sales revenues are generally recognized when we ship products from our facility to our customer. The product sales for our Completion Fluid & Products Division consist primarily of clear brine fluids ("CBFs"), additives, and associated manufactured products. Product sales for our Water & Flowback Services Division are typically attributed to specific performance obligations within certain production testing service arrangements. Parts and equipment sales comprise the product sales for the Compression Division.

Services. Service revenues represent revenue recognized over time, as our customer arrangements typically provide agreed upon day-rates (monthly service rates for compression services) and we recognize service revenue based upon the number of days services have been performed. Service revenue recognized over time is associated with a majority of our Water & Flowback Services Division arrangements, compression service and aftermarket service contracts within our Compression Division, and a small portion of Completion Fluids & Products Division revenue that is associated with completion fluid service arrangements. With the exception of the initial terms of the compression services contracts for medium- and high-horsepower compressor packages of our Compression Division, our customer contracts are generally for terms of one year or less. The majority of the service arrangements in the Water & Flowback Services Division are for a period of 90 days or less. Within our Compression Division service revenue, most aftermarket service revenues are recognized at a point in time when we transfer control of our products and complete the delivery of services to our customers.

We receive cash equal to the invoice price for most product sales and services and payment terms typically range from 30 to 60 days from the date we invoice our customer. Since the period between when we deliver products or services and when the customer pays for such products or services is not expected to exceed one year, we have elected not to calculate or disclose a financing component for our customer contracts.

Depending on the terms of the arrangement, we may also defer the recognition of revenue for a portion of the consideration received because we have to satisfy a future performance obligation. For example, consideration received from customers during the fabrication of new compressor packages is typically deferred until control of the compressor package is transferred to our customer. For any arrangements with multiple performance obligations, we use management's estimated selling price to determine the stand-alone selling price for separate performance obligations. For revenue associated with mobilization of service equipment as part of a service contract arrangement, such revenue, if significant, is deferred and amortized over the estimated service period. As of June 30, 2019, we had $45.3 million of remaining performance obligations related to our compression service contracts. As a practical expedient, this amount does not reflect revenue for compression service contracts whose original expected duration is less than 12 months and does not consider the effects of the time value of money. The remaining performance obligations are expected to be recognized through 2022 as follows (in thousands):



	2019		2020		2021		2022		2023		Total
	(In Thousands)
Compression service contracts remaining performance obligations	$	19,830	$	19,279	$	6,108	$	101	$	—	$	45,318

Sales taxes, value added taxes, and other taxes we collect concurrent with revenue-producing activities are excluded from revenue. We have elected to recognize the cost for freight and shipping costs as part of cost of product sales when control over our products (i.e. delivery) has transferred to the customer.

Use of Estimates. In recognizing revenue for variable consideration arrangements, the amount of variable consideration recognized is limited so that it is probable that significant amounts of revenues will not be reversed in future periods when the uncertainty is resolved. For products returned by the customer, we estimate the expected returns based on an analysis of historical experience. For volume discounts earned by the customer, we estimate the discount (if any) based on our estimate of the total expected volume of products sold or services to be provided to the customer during the discount period. In certain contracts for the sale of CBF, we may agree to issue credits for the repurchase of reclaimable used fluids from certain customers at an agreed price that is based on the condition of the fluids. For sales of CBF, we adjust the revenue recognized in the period of shipment by the estimated amount of the credit expected to be issued to the customer, and this estimate is based on historical experience. As of June 30, 2019, the amount of remaining credits expected to be issued for the repurchase of reclaimable used fluids was $4.2 million that were recorded in inventory (right of return asset) and accounts payable. There were no material differences between amounts recognized during the three and six month periods ended June 30, 2019, compared to estimates made in a prior period from these variable consideration arrangements.

Contract Assets and Liabilities. We consider contract assets to be trade accounts receivable when we have an unconditional right to consideration and only the passage of time is required before payment is due. In certain instances, particularly those requiring customer specific documentation prior to invoicing, our invoicing of the customer is delayed until certain documentation requirements are met. In those cases, we recognize a contract asset rather than a billed trade accounts receivable until we are able to invoice the customer. Our contract asset balances, primarily associated with these documentation requirements, were $35.4 million and $44.2 million as of June 30, 2019 and December 31, 2018, respectively. Contract assets, along with billed trade accounts receivable, are included in trade accounts receivable in our consolidated balance sheets.

We classify contract liabilities as Unearned Income in our consolidated balance sheets. Such deferred revenue typically results from advance payments received on orders for new compressor equipment prior to the time such equipment is completed and transferred to the customer in accordance with the customer contract.

The following table reflects the changes in our contract liabilities for the periods indicated:



	Six Months Ended June 30,
	2019			2018
	(In Thousands)
Unearned Income, beginning of period	$	25,333		$	17,050
Additional unearned income	84,456			59,360
Revenue recognized	(78,119		)	(47,276		)
Unearned income, end of period	$	31,670		$	29,134

During the six month period ended June 30, 2019, we recognized in product sales revenue of $19.1 million from unearned income that was deferred as of December 31, 2018. During the six months ended June 30, 2018, we recognized in product sales revenue of $15.4 million from unearned income that was deferred as of our adoption of ASC 606 on January 1, 2018.

Contract Costs. As of June 30, 2019, contract costs were immaterial.

Disaggregation of Revenue. We disaggregate revenue from contracts with customers into Product Sales and Services within each segment, as noted in our three reportable segments in Note I. In addition, we disaggregate revenue from contracts with customers by geography based on the following table below.



	Three months ended June 30,			Six months ended June 30,
	2019	2018		2019		2018
	(In Thousands)
Completion Fluids & Products
U.S.	37,536	34,112		$	69,142	$	62,020
International	42,231	42,444		72,206		67,640
	79,767	76,556		141,348		129,660
Water & Flowback Services
U.S.	68,412	70,838		141,611		117,877
International	4,712	12,808		10,191		26,844
	73,124	83,646		151,802		144,721
Compression
U.S.	126,122	90,927		219,638		167,907
International	9,783	8,997		19,736		17,439
	135,905	99,924		239,374		185,346
Interdivision eliminations
U.S.	—	—		—		1
International	—	(54	)	—		(275		)
	—	(54	)	—		(274		)
Total Revenue
U.S.	232,070	195,877		430,391		347,805
International	56,726	64,195		102,133		111,648
	288,796	260,072		$	532,524	$	459,453