For the three months ended March 31, 2013, depletion expense decreased $3.5 million to $4.6 million from $8.1 million during the same period in 2012 primarily due to the sale of a 49% participating interest in the Block Z-1 license contract.
For the three months ended March 31, 2013, the Company's share of standby costs was $1.1 million including the CX-11 workover rig and the CX-15 drilling rig. For the three months ending March 31, 2012, the Company incurred $1.2 million of standby rig costs.
For the three months ended March 31, 2013, other expense decreased $7.5 million to $5.2 million compared to $12.7 million for the same period in 2012. The decrease is primarily due to $1.9 million of lower net interest expense resulting from lower interest bearing debt outstanding between the two periods, and a $5.9 million decrease in losses on derivatives due to lower crude oil prices during the 2013 quarter.
For the three months ended March 31, 2013, the Company recognized income tax expense of $0.3 million on a loss before income taxes of $12.5 million. For the comparable 2012 period, the Company recognized an income tax benefit of $4.3 million on a loss before income taxes of $31.6 million. The decrease in the loss before income taxes is mainly a result of the lower GG&E expenses, partially offset by the impact on operating income from the sale of a 49% participating interest in the Z -1 license contract to Pacific Rubiales.
Liquidity, Capital Expenditures and Capital Resources
At March 31, 2013, the Company had cash and cash equivalents of $63.0 million and restricted cash of $66.5 million, an accounts receivable balance of $45.6 million and working capital of $54.1 million.
Capital and Exploratory Expenditures
The Company's non-Block Z-1 total capital and exploratory expenditures for the first quarter ended March 31, 2013 were $0.6 million, excluding capitalized interest of $2.6 million.