Apr. 2012 - In 2011, Tullow completed an exploration and appraisal program on the TEN cluster project enabling the beginning of FEED work. FEED work has commenced on the FPSO and subsea infrastructure options with a Plan of Development are expected to be submitted to the Government of Ghana in the third quarter of 2012. Tullow expects first oil to commence some 30 months after approval with combined production in the region of 100,000 bopd. Initial gas production will be split between export and re-injection to manage reservoir performance.

Mar. 2012 - Tullow has identified several prospects in the Deepwater Tano license offshore Ghana. Three exploration wells are expected to be drilled on the block before 2013, which include: Wawa-1, Sapele-1 and Tweneboa Deep-1. Tullow said that Wawa-1 will target hydrocarbons which may have moved to a trap up-dip from the TEN oil and gas/condensate fields; Sapele-1, immediately south of the Jubilee field, will test a prospective turbidite lobe and Tweneboa Deep-1, is a material prospect below the TEN fields.

Mar. 2012 - Tullow Oil has successfully appraised the Enyenra-4A well in the Deepwater Tano License offshore Ghana. The well encountered oil in very good quality sandstone reservoirs. The company said that good evidence of communication with the Owo-1 discovery wells and the Enyenra appraisal wells confirm the extent of the Enyenra light oil field. Enyenra-4A, located 4.5 miles (7 kilometers) south west of Enyenra-2A and almost 13 miles (21 kilometers) south of the Enyenra-3A well, was drilled to define the southern extent of the field. Results of drilling, wireline logs, samples of reservoir fluids and pressure data show that Enyenra-4A has intersected 105 feet (32 meters) of net oil pay. Pressure data from the oil leg has demonstrated that the oil is in static communication with the oil seen in the other wells in the field, indicating a continuous oil column of approximately 1,970 feet (600 meters). The well will be suspended for later use. The Ocean Olympia (UDW drillship) drilled the well to a total depth of 13,695 feet (4,174 meters) in a water depth of 6,160 feet (1,878 meters).

Jan. 2012 - Kosmos Energy has successfully appraised the Ntomme-2A well in the Deepwater Tano Block offshore Ghana, encountering significant quantities of light oil. The well was designed to test the potential of an oil leg beneath the previously-identified gas-condensate at Ntomme. Results of drilling, wireline logs and fluid samples indicate that the well encountered 148 feet (45 meters) of high-quality stacked reservoir sandstones, including 128 feet (39 meters) of 35 degree API gravity net oil pay. Pressure data from the well and the original discovery well suggests the potential of an oil column at Ntomme at about 410 feet (125 meters) below the gas-condensate accumulation. Ntomme-2A was drilled to an interim depth of 12,812 feet (3,905 meters) in a water depth of 5,675 feet (1,730 meters). Once drilling operations are completed, a drill stem test will be performed.

Nov. 2011 - Kosmos Energy is currently redrilling the Enyenra-1 discovery well in the Deepwater Tano block. The operator plans to conduct a drill stem test at the site. Once operations are completed, Kosmos will spud the Enyenra-4 appraisal well, located about four miles downdip from Enyenra-2, on the south flank of the discovery. Results are expected in the first quarter of 2012. Tullow (49.95 percent) operates the Deepwater Tano license and is partnered by Kosmos Energy (18 percent), Anadarko Petroleum (18 percent), Sabre Oil & Gas (4.05 percent) and the Ghana National Petroleum Corporation (10 percent carried interest).

Sep. 2011 - Tullow Oil's Enyenra-3A appraisal well encountered oil in high-quality sandstone reservoirs, located in the Deepwater Tano license offshore Ghana. According to pressure data, the Enyenra-3A well has confirmed an up-dip extension of the Enyenra oil field. Results of drilling, wire line logs, samples of reservoir fluids and pressure data found that Enyenra-3A has intersected 56 feet (17 meters) of 35 degree API oil, and a continuous oil column of at least 1,198 feet (365 meters). Data has revealed that the oil at Enyenra-3A is in static pressure communication with both the Owo-1 discovery well and the Enyenra-2A appraisal well. Drilled by the Deepwater Millennium drillship, the well reached a total depth of 13,225 feet (4,031 meters) in a water depth of 3,615 feet (1,102 meters). Once drilling operations are completed, pressure gauges will be deployed in the Enyenra-2A and Enyenra-3A wells to determine reservoir connectivity. The operator will then drill the Enyenra-4A well using the Sedco Energy semisub to further evaluate the downdip extent of the field. Tullow (49.95%) operates the Deepwater Tano license and is partnered by Kosmos Energy (18%), Anadarko Petroleum (18%), Sabre Oil & Gas (4.05%) and the Ghana National Petroleum Corporation (10% carried interest).

May. 2011 - Tullow Oil announced its forward exploration program for the Deepwater Tano license includes well tests on the Enyenra and Tweneboa fields and two additional appraisal wells on Enyenra. The operator plans to submit a combined plan of development to the Government of Ghana in the beginning of 2012. Tullow Oil operates the license, holding a 49.95% interest; Kosmos Energy holds 18%; Anadarko holds 18%; Sabre Oil & Gas holds 4.05%; and the Ghana National Petroleum Corporation holds 10%.

Apr. 2011 - Tullow Oil has encountered gas-condensate in its Tweneboa-4 appraisal well in the Deepwater Tano license offshore Ghana. Data that was collected while drilling has confirmed that the gas-condensate accumulation extends to the western flank of the Tweneboa field. Tweneboa-4 encountered 59 feet (18 meters) of net gas condensate pay in high-quality stacked reservoir sandstones which are in communication with both the Tweneboa-1 and Tweneboa-2 wells. The Deepwater Millennium drillship drilled the well to a total depth of 13,146 feet (4,007 meters) in a water depth of 4,711 feet (1,436 meters). The well will be suspended for future use in the field's appraisal and development, and then the rig will move to the Tweneboa-2 location to perform a drill stem test. Tullow operates the Deepwater Tano license, holding a 49.95% interest; Kosmos Energy Ghana holds 18%; Anadarko holds 18%; Sabre Oil & Gas holds 4.05%; and Ghana National Petroleum (GNPC) holds the remaining interest.

Mar. 2011 - Tullow has encountered oil in excellent quality sandstone reservoirs in the Enyenra-2A (formerly Owo) appraisal well in the Deepwater Tano license offshore Ghana. The appraisal and discovery well show evidence of good communication, confirming that the Owo (Enyenra) oil discovery is a major light oil field. Situated about 4 miles (7 kilometers) south and down-dip of Owo-1, the well was drilled to appraise the Upper and Lower channels of the Enyenra oil field. Results from gathered data show that Enyenra-2A has intersected 69 feet (21 meters) of net oil pay in the Upper Channel and 36 feet (11 meters) of net oil pay in the Lower Channel. Pressure data from the Upper Channel has also demonstrated that the oil is in communication with the Owo-1 well; and oil pressures in the Lower Channel suggest it may also be in communication with the deeper pools seen in the discovery well and its sidetrack. The Enyenra-2A well also tested a deeper Turonian fan where 16 feet (5 meters) of gas-condensate bearing sandstones were intersected. Tullow stated that interpretation of the extent and thickness of this zone away from the well is ongoing. Drilled to a total depth of 13,891 feet (4,234 meters) by the Deepwater Millennium drillship, the Enyenra-2A well is located in a water depth of 5,492 feet (1,674 meters). Once operations are completed, the well will be suspended for later use. The drillship will remain in the Deepwater Tano block to complete the drilling of the Tweneboa-4 well. The next appraisal well will be the Enyenra-3A, located up-dip to the north of the Owo-1 discovery. Tullow operates the block, holding a 49.95% interest; Kosmos Energy holds 18%; Anadarko Petroleum holds 18%; Sabre Oil and Gas holds 4.05%; and the Ghana National Petroleum Corporation holds a 10% carried interest.

Jan. 2011 - Tullow's Tweneboa-3 appraisal well has encountered gas condensate in excellent quality sandstone reservoirs; and drilling results, wireline logs and fluid samples from the well confirm the greater Tweneboa area resource base potential. The well was planned with two deviated boreholes to test separate areas of the Tweneboa field, stated the operator. The first leg was drilled to calibrate the potential of an area with a weak seismic response. This leg encountered thin reservoir sands and about 30 feet (9 meters) of gas condensate pay. The well was then sidetracked about 1,804 feet (550 meters) west, targeting the Ntomme anomaly, an area of strong seismic response. This leg encountered a gross vertical reservoir interval of about 213 feet (65 meters) containing 112 feet (34 meters) of net gas condensate pay in two zones of high-quality stacked reservoir sandstones. Currently, work is underway to integrate seismic, pressure and hydrocarbon data in order to progress development options for the Tweneboa and Enyenra (Owo) fields in the greater Tweneboa area. Drilled by the Deepwater Millennium drillship, the well reached a total depth of 12,815 feet (3,906 meters) in a water depth of 5,253 feet (1,601 meters). Once operations are completed, the well will be suspended for future use in the field’s development. The rig will remain in the block to drill the top-hole section of the Tweneboa-4 appraisal well. Tweneboa is located in the Deepwater Tano License offshore Ghana on Block 2, and is operated by Tullow Oil.

Sep. 2010 - The drilling of the Owo-1 exploratory sidetrack well has extended the column of high quality light oil discovered by the Owo-1 well. The results from drilling, wireline logs and samples of reservoir fluids have confirmed that Owo is a major new oil field. The Owo-1 well encountered 174 feet (53 meters) of net oil pay, and the sidetrack well encountered an additional 52 feet (16 meters) of net oil pay in the lower part of the same channel system. Pressure data has indicated that the oil pay communicates with the reservoirs penetrated in the Owo-1 well, confirming at least 226 feet (69 meters) of total net oil pay in a substantial gross oil column of 656 feet (200 meters). Lying beneath the Owo oil field, 43 feet (13 meters) of additional net condensate pay was also discovered, with an additional 20 feet (6 meters) of net gas pay logged in the deepest sand encountered. Water was not encountered in any of the hydrocarbon-bearing reservoirs. Once logging is completed, the well will be suspended for future use in appraisal and development operations. Drilled by the Sedco 702 semisub, the well reached a final depth of 13,117 feet (3,998 meters) in waters measuring 4,685 feet (1,428 meters). Tullow (49.95%) operates the Deepwater Tano license and is partnered by Kosmos Energy Ghana (18%), Anadarko Petroleum (18%), Sabre Oil & Gas (4.05%) and the Ghana National Petroleum Corporation (GNPC) (10% carried interest).

Jul. 2010 - Tullow Oil intersected a significant amount of light oil in the Owo-1 exploration well in the Deepwater Tano license offshore Ghana, potentially adding a billion barrels of oil equivalent to the resource estimate for the area. The deviated well encountered a gross vertical reservoir interval of 505 feet (154 meters) containing 174 feet (53 meters) of net oil pay in two zones of high-quality stacked reservoir sandstones. Pressure data indicates that these zones are part of the same accumulation, and samples show that the oil is light, between 33 and 36 degrees API. Following the completion of logging operations, the well will be sidetracked .4 miles (.6 kilometers) to the east to provide additional information on lateral reservoir distribution, and to intersect a deeper part of the Owo channel system. Drilled by the Sedco 702 semisub, the well reached a final depth of 12,766 feet (3,891 meters) in a water depth of 4,685 feet (1,428 meters). Tullow Oil operates the license, holding a 49.95% interest; Kosmos Energy holds 18%; Anadarko holds 18%; Sabre Oil & Gas holds 4.05%; and the Ghana National Petroleum Corporation holds 10%.

Jan. 2010 - Drilling results, wireline logs and fluid samples from the Tweneboa-2 appraisal well proved that the well intersected a significant oil and gas-condensate column. Encountering 105 feet (32 meters) of net hydrocarbon pay (comprised of a 56 foot [17 meter] oil bearing zone resting below a 49 foot [15 meter] gas condensate bearing zone) in a gross reservoir interval of 502 feet (153 meters), the Tweneboa-2 well has established a combined hydrocarbon column of at least 1,148 feet (350 meters) stretching from the lowest known oil in Tweneboa-2 to the top of the gas-condensate in Tweneboa-1. With this information indicating a highly prospective and extensive turbidite fan system, additional drilling will be performed to evaluate the prospect. After completing log operations, the appraisal well will be deepened to test further exploration potential beneath the Tweneboa field, and the well will then be suspended with the intent to perform additional appraisal and development operations at the site in the future. Drilled by the Atwood Hunter semisub, the well reached an interim depth of 12,664 feet (3,860 meters) in a water depth of 4,334 feet (1,321 meters). Tweneboa is located in the Deepwater Tano License offshore Ghana on Block 2, and is operated by Tullow Oil.

Mar. 2009 - Tullow announced its Tweneboa-1 well was deepened to 12,920 feet (3,938 meters) and encountered 13 feet (4 meters) of highly-pressured oil bearing sands, as well as an over-pressured zone at total depth. Drilled by the Eirik Raude semisub in a water depth of 3,766 feet (1,148 meters), the field is 16 miles (25 kilometers) west of the Jubilee Field offshore Ghana.

Mar. 2009 - The Tweneboa-1 well in the Deepwater Tano license offshore Ghana encountered 69 feet (21 meters) of net pay. Drilled by the Eirik Raude semisub in 3,766 feet (1,148 meters) of water, the field is located 16 miles (25 kilometers) west of the Jubilee Field. Further drilling is required to test core areas. Tullow is the operator of the license with 49.95%.