Publications

Chevron Pacific Indonesia (CPI) has been operating in Indonesia for years, consistently producing crude oil from its giant oilfield located in Sumatera island. Duri field is one of the backbone field in Sumatera which has unconsolidated permeable reservoir characteristic containing heavy oil with 21API gravity. The shallow horizontal campaign already started in early 2000 targeted P formation (600-900ft TVD) using vertical rig with top drive. As this deeper reservoir drained, the remaining oil has no longer economic. Therefore, the reservoir target then moves to R formation which has shallower depth (350-500 ft TVD). However, drilling this shallower target formation contain multiple challenges. These challenges are: the ability of casing to withstand the bending from high dogleg severity, directional drilling capability and loss circulation. Beside these technical challenges, low oil price condition and PSC contract approaching end also contribute to complexity of the drilling these shallow horizontal wells. To answer the challenges, some novel fit-for-purpose strategy is implemented. Modifying casing-hole hierarchy to make the clearance larger (10-3/4” surface casing with 17-1/2” hole and 7” casing with 9-7/8” hole) succeed to manage the high bending load due to dogleg severity. Integrated design of BHA, well trajectory and drilling parameter has led to successful directional control. Blind drilling is implemented to minimize NPT due to loss circulation. These strategies successfully deliver 54 shallow horizontal wells targeting R formation with MD/TVD ratio until 5.4, Lateral Length/Landing Length ratio until 1.69, TVD at Landing Point until 356.6 ft and cycle time to complete single well is 7 days in average by 2017.