4. SUPPLEMENTAL CONSOLIDATED FINANCIAL STATEMENT INFORMATION

Disaggregated Revenues

The Company has one line of business, acquiring and processing seismic data in North America. Our chief operating decision maker (President, Chief Executive Officer and Chairman of the Board) makes operating decisions and assesses performance based on the Company as a whole. Accordingly, the Company is considered to be in a single reportable segment. The following table presents the Company’s operating revenues (unaudited and in thousands) disaggregated by geographic region:


	Three Months Ended June 30,				Six Months Ended June 30,
	2019		2018			2019	2018
Operating Revenues
United States	$	22,046	$	35,288	$	59,682	$	73,065
Canada		2,030		870		15,558		12,973
Total	$	24,076	$	36,158	$	75,240	$	86,038

Deferred Costs (in thousands)

The opening balance of deferred cost was $6,994 and $2,991 at January 1, 2019 and 2018, respectively. The Company’s prepaid expenses and other current assets at June 30, 2019 and 2018 included deferred costs incurred to fulfill contracts with customers of $4,590 and $7,367, respectively.

Deferred costs at June 30, 2019 compared to January 1, 2019 decreased primarily as a result of the completion of several projects during that six month period that had significant deferred fulfillment costs at January 1, 2019. Deferred cost at June 30, 2018 compared to January 1, 2018 increased primarily as a result of new projects for clients with significant deferred fulfillment costs at June 30, 2018.

The amount of total deferred costs amortized for the second quarter and first six months of 2019 was $7,542 and $20,447, respectively. The amount of total deferred costs amortized for the second quarter and first six months of 2018 was $7,248 and $14,247, respectively. There were no material impairment losses incurred during these periods.

Deferred Revenue (in thousands)

The opening balance of deferred revenue was $10,501 and $6,314 at January 1, 2019 and 2018, respectively. The Company’s deferred revenue at June 30, 2019 and 2018 was $8,538 and $7,103, respectively.

Deferred revenue at June 30, 2019 compared to January 1, 2019 decreased primarily as a result of completing projects for clients with large prepayments for third party reimbursables. Deferred revenue at June 30, 2018 compared to January 1, 2018 remained fairly consistent.

Revenue recognized for the second quarter and first six months of 2019 that was included in the contract liability balance at the beginning of 2019 was $1,284 and $8,177, respectively. Revenue recognized for the second quarter and first six months of 2018 that was included in the contract liability balance at the beginning of 2018 was $1,628 and $5,311, respectively.