Changes reflect capital in excess of par. Ltd and Noble Energy, Inc. acquisitions, respectively. In addition, the company recruits experienced hires to target critical skills. The Board provides oversight of CEO and executive succession planning. Recent surveys have indicated a high degree of employee engagement. Wells Drilling1Net Wells Completed at 12/31/20202020192018Gross Net Prod. Chevron also holds nonoperated interests in several shelf fields. Both fields are company operated. Additional development opportunities for the Jack and St. Malo fields progressed in 2020. Proved reserves have been recognized for the multiphase subsea pump project. The Jack and St. Malo fields have an estimated production life of 30 years. The company has a 58 percent-owned and operated interest in the deepwater Tahiti Field. Two exploration wells were drilled in the first half of 2020. Exploration activities continued in 2020. Acreage for Africa can be found in the table on page 7. The plant has the capacity to process 1.1 billion cubic feet of natural gas per day. Chevron also holds a 27 percent interest in adjacent licenses OML 139 and OML 154. Concessions for the producing areas within this basin expire between 2036 and 2040. At the end of 2020, proved reserves had not been recognized for this project. Three additional wells were completed in 2020. Net daily oil-equivalent production can be found in the table on page 6. The project's estimated economic life exceeds 30 years. Project start-up is expected in second quarter 2021. The company markets in Latin America using the Texaco brand. The company also operates through affiliates under various brand names. Upstream assets may also become impaired. Chevron has filed an appeal of this order. The parties are negotiating a resolution of these issues with the agencies. There are no restrictions on the company's ability to pay dividends. The Brent price averaged $42 per barrel for the full-year 2020, compared to $64 in 2019. The reserve replacement ratio in 2020 was 74 percent. This led to lower price realizations across all commodities. Production has also been curtailed due to market conditions, most notably in Thailand. Unfavorable tax items of $110 million also contributed to the decrease. Foreign currency effects increased net charges by $210 million between periods. More information on bond issuances is included in Note 18 on page 84. These amounts were partially offset by repayment of long-term notes that matured in 2020. ROSE is a ratio intended to measure earnings as a percentage of shareholder investments. Information on employee benefit plans is contained in Note 21 beginning on page 87. At year-end 2020, the company had no interest rate swaps. These asset retirement obligations include costs related to environmental issues. Refer to Note 23 on page 94 for additional discussions on asset retirement obligations. Total pension expense for 2020 was $1.5 billion. The company uses all available information to make these fair value determinations. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. CUSA and its subsidiaries manage and operate most of Chevron's U.S. businesses. As a result, the company believes concentrations of credit risk are limited. The company routinely assesses the financial strength of its customers. No borrowings were outstanding under this facility at December 31, 2020. These awards retained the same provision as the original Noble Plans. A