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 September 30,				Nine Months Ended September 30,
	2019		2018			2019	2018
Operating Revenues
United States	$	36,814	$	39,950	$	96,496	$	113,015
Canada		162		498		15,720		13,471
Total	$	36,976	$	40,448	$	112,216	$	126,486

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 September 30, 2019 and 2018 included deferred costs incurred to fulfill contracts with customers of $3,157 and $7,001, respectively.

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

The amount of total deferred costs amortized for the third quarter and first nine months of 2019 was $6,806 and $27,253, respectively. The amount of total deferred costs amortized for the third quarter and first nine months of 2018 was $14,757 and $29,004 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 September 30, 2019 and 2018 was $7,970 and $2,779, respectively.

Deferred revenue at September 30, 2019 compared to January 1, 2019 and at September 30, 3018 compared to January 1, 2018 decreased primarily as a result of completing projects for clients with large prepayments for third party reimbursables.

Revenue recognized for the third quarter and first nine months of 2019 that was included in the contract liability balance at the beginning of 2019 was $427 and $8,604, respectively. Revenue recognized for the third quarter and first nine months of 2018 that was included in the contract liability balance at the beginning of 2018 was $634 and $5,945, respectively.