Revenue

6 Months Ended

Jun. 30, 2019

Revenue is recognized based on the transfer of control or our customers' ability to benefit from our services and products in an amount that reflects the consideration we expect to receive in exchange for those services and products. The vast majority of our service and product contracts are short-term in nature. In recognizing revenue for our services and products, we determine the transaction price of purchase orders or contracts with our customers, which may consist of fixed and variable consideration. We also assess our customers' ability and intention to pay, which is based on a variety of factors, including our customers' historical payment experience and financial condition. Payment terms and conditions vary by contract type, although terms generally include a requirement of payment within 20 to 60 days. Other judgments involved in recognizing revenue include an assessment of progress towards completion of performance obligations for certain long-term contracts, which involve estimating total costs to determine our progress towards contract completion and calculating the corresponding amount of revenue to recognize.

Disaggregation of revenue

We disaggregate revenue from contracts with customers into types of services or products, consistent with our two reportable segments, in addition to geographical area. Based on the location of services provided and products sold, 54% and 59% of our consolidated revenue was from the United States for the six months ended June 30, 2019 and 2018, respectively. No other country accounted for more than 10% of our revenue. The following table presents information on our disaggregated revenue.



Millions of dollars	Three Months Ended June 30				Six Months Ended June 30
Revenue by segment:	2019		2018		2019		2018
Completion and Production	$	3,805	$	4,164	$	7,467	$	7,971
Drilling and Evaluation	2,125		1,983		4,200		3,916
Total revenue	$	5,930	$	6,147	$	11,667	$	11,887
Revenue by geographic region:
North America	$	3,327	$	3,834	$	6,602	$	7,351
Latin America	571		479		1,158		936
Europe/Africa/CIS	823		726		1,571		1,442
Middle East/Asia	1,209		1,108		2,336		2,158
Total revenue	$	5,930	$	6,147	$	11,667	$	11,887

Contract balances

We perform our obligations under contracts with our customers by transferring services and products in exchange for consideration. The timing of our performance often differs from the timing of our customer’s payment, which results in the recognition of receivables and deferred revenue. Deferred revenue represents advance consideration received from customers for contracts where revenue is recognized on future performance of service. Deferred revenue, as well as revenue recognized during the period relating to amounts included as deferred revenue at the beginning of the period, was not material to our condensed consolidated financial statements.

Transaction price allocated to remaining performance obligations

Remaining performance obligations represent firm contracts for which work has not been performed and future revenue recognition is expected. We have elected the practical expedient permitting the exclusion of disclosing remaining performance obligations for contracts that have an original expected duration of one year or less. We have some long-term contracts related to software and integrated project management services such as lump sum turnkey contracts. For software contracts, revenue is generally recognized over time throughout the license period when the software is considered to be a right to access our intellectual property. For lump sum turnkey projects, we recognize revenue over time using an input method, which requires us to exercise judgment. Revenue allocated to remaining performance obligations for these long-term contracts is not material.