Perus crude Oil production is concentrated in the northern part of the country. In particular, the largest oil blocks are Block 1-AB (Pluspetrol) along the border with Ecuador, Block 8 (Pluspetrol) in the northeastern Amazon region, Block X (Petrobras) in the northwest, and Block Z-2B (Petro-Tech Peruana) off the northwest coast. Block 1-AB and 8 account for over 65 percent of Perus total Crude Oil production. Most of crude oil produced in Peru is a heavy, sour variety known as Lorento, with 20° API and 1.2 percent sulfur content.