(Adds details of the project)
BANGKOK, Sept 22 (Reuters) - Thailand's top oil and gas explorer, PTT Exploration and Production Pcl, has agreed to acquire a 20 percent stake in Brazilian offshore oil and gas concession BM-ES-23 from Royal Dutch Shell for an undisclosed sum.
The acquisition is a milestone for PTTEP's expansion in South America, a region with high petroleum potential, the Thai firm said in a statement on Monday.
The concession is located in the Espirito Santo Basin, in a deepwater block covering about 550 square km (212 square miles). The joint venture partners plan to conduct exploration and appraisal drilling in 2014 and 2015, the statement said.
The agreement is subject to approval from Brazil's National Agency of Petroleum, Natural Gas and Biofuels. Petrobras , operator of the block, will hold 65 percent and Inpex Corp 15 percent.
PTTEP, the flagship company of state-controlled PTT Pcl , made its first investment in Brazil in April 2014 and holds 25 percent in four exploration deepwater blocks in Barreirinhas basin in the Atlantic Ocean.
PTTEP, ranked among Asia's top 10 explorers, is scouting for oil and gas assets to boost energy security in Thailand.
The company aims for 10 percent growth in petroleum sales this year and wants to double output to 600,000 barrels of oil equivalent per day (BOEPD) by 2020. (Reporting by Khettiya Jittapong; Editing by Alan Raybould)