Publications

Bunyu Field is one of PT PERTAMINA EP’s oil and gas field backbone, located at North Kalimantan. The challenge of Bunyu’s geological setting is the spreading area of the reservoirs, sometimes there is no sand connectivity in reservoirs of 150 metres between two separate wells. On the other hand, sometimes new prospect zones were found. Formation pressure measurement is very important to know the vertical permeability and to detect fluid contact movement. In the last few years, formation pressure measurement was taken by wireline formation tester but it often got stuck due to well profile and coal layers. In 2014, formation pressure measurement while drilling was used to decrease stuck risks which often happened in the previous wells. The method of this pressure measurement while drilling is quite similar to the wireline formation tester. After making sure the tool is set on the right depth by gamma ray correlation, downlink is sent to activate the pad/probe. Mud circulation is kept on going during the acquisition to make sure the hole is clean. Data directly derived from the formation are pressure and mobility. This technology was well applied at RR-015 Well. Twenty two points were taken with the result 18 points of good pretest, 2 points showed pressures werenot stabilized, and 1 supercharged. Evaluation of the tests takenshows a barrier between a sand body and some points show depleted reservoirs. This measurement was done in about 20 hours without any operational problems. This technology has proven to measure formation pressure succesfully in a thin laminated deltaic environment with good result and could be an alternative to replace wireline tool in high risk wells.