Nigeria shares a Joint Development Zone (JDZ) with neighboring SÃo TomÉ and PrÍncipe (STP), which contains 23 exploration blocks. Nigeria and Sao Tome have agreed to split revenues from the blocks on a 60:40 basis, respectively. Block One is currently the only block in the JDZ undergoing development. The block is controlled by Chevron (51 percent), with partners ExxonMobil (40 percent) and Equity Energy Resources (9 percent). Preliminary studies have indicated that the block could contain sizable amounts of Oil (up to 1 billion barrels). If recoverable oil is located, Chevron plans to bring it onstream by 2010. Blocks Two through Six were also awarded, of which, three have been approved for PSAs, while the remaining two have yet to be signed. Meanwhile, several independent U.S. based companies that were awarded shares in the blocks have relinquished their awards. Pioneer Natural Resources stated a failure to agree to specific terms of operation on Block Two as the reason for its withdrawal from the project. Pioneers withdrawal has opened the door for Chinas oil and gas company, Sinopec, to invest in the JDZ.ExxonMobil produces around 750,000 bbl/d of oil in Nigeria. The company plans to invest $11 billion in the countrys oil sector through 2011, with the hope of increasing production to 1.2 million bbl/d. The majority of the increase will occur at the Erha field, which is located on Block OPL 209. ExxonMobil began producing oil from Erha in April 2006. Output from the field is expected to reach 150,000 bbl/d by the third quarter of 2006, and rise to 190,000 bbl/d by the end of the year. Oil from Erha is stored in an FPSO, with a storage capacity of 2.2 million barrels oil. ExxonMobil uses Very Large Crude Carriers (VLCC), capable of holding up to 300,000 deadweight tons to export the oil from the terminal. The company also operates the Yoho field, with current full-field output of around 150,000 bbl/d. Yoho contains around 400 million barrels of oil reserves. ExxonMobil is continuing to expand Yoho field and estimates the expansion project will increase production to 170,000 bbl/d by the third quarter of 2006. The $1.2 billion field is located in the shallow waters of Block OML 104. ExxonMobils Bosi, and Eti/Asasa fields with capacities of 120,000 bbl/d, and 25,000 bbl/d, respectively, are scheduled to come online between 2006 and 2007.