China: Second Zitong deep gas find tested

By OGJ editors
HOUSTON, Jan. 17 – The Zitong-1 well on the Zitong exploration block in China’s Sichuan basin tested at a restricted 750 Mcfd of gas on a 3-mm choke from 33 m of pay in the Xu-4 tight sand formation, said Ivanhoe Energy Inc. unit Sunwing Energy Ltd.

The company plans to test the more conventional Xu-5 sand formation, in which logs indicate porosity is 10-14%. The Xu-2 zone, productive in third-party wells in the area, was too tight to achieve commercial rates in Zitong-1. The three formations are candidates for horizontal drilling and multistage frac stimulation, the company said.

After the company’s Dec. 21, 2010, test of the Yixin-2 well at 13 MMcfd on the block, Sunwing tested the well at a lower, controlled rate of 1.25 MMcfd to 1.5 MMcfd for 48 hr and then shut-in for 21 days to obtain pressure data. The Xu-4 flow rates are consistent with what is observed in tight, fractured sandstones that rely on stimulation to generate commercial flow rates.