Delivering a One Phase Well Under Two Days with a One Inch Cutter PDC Drill Bit: A Record Breaking Performance in Mature Field, Drilling Optimization Case History

Abstract

Mahakam Block is a huge oil and gas concession managed by PT. Pertamina Hulu Mahakam (PHM) and located in deltaic and offshore environment in East Kalimantan, Indonesia. Until today, the field has produced oil and gas for more than 50 years and categorized as "brown field" due to its declining production and marginal reserve potential. This condition has led to numerous effort to boost efficiency in well delivery from drilling perspective such that the reserve could be produced more economically. One of the effort that has been done to create a well to be more economical is by increasing the Rate of Penetration (ROP). An increase in ROP would directly impact on well duration that could be finished faster in such that it would also impact on much lower well cost. There are several key factors that influence ROP, yet the most crucial part is coming from drilling bit design that is used to drill the formation. Incompatibility between bit design with formation and directional drive type would often result in slow drilling progress and thus would make a well less profitable. To support this idea, the operator has launched a campaign called MAXIDRILL with aim to have a persistent excellent drilling performance from ROP perspective. Selective approach to different bit designs and bit suppliers has brought the operator to conduct the first trial in Indonesia utilizing a one inch PDC cutter drill bit. Besides the effort to increase well economics by increasing ROP using various bit designs through MAXIDRILL Campaign, PHM also tries to implement new set of well architecture dedicated specifically for developing the shallow hydrocarbon zone in Mahakam in general, and in Tunu Field in particular. With this new type of architecture, it allows drilling with 9-1/2″ hole to be done straight from 20″ Conductor Pipe down to well final target depth in single phase, where next 3-1/2″ production tubing will be run and cemented in place. The new design of architecture is called "One Phase Well". This novel innovation was initiated in 2019, where to date, the operator has drilled more than 30 wells without any incident. With the learning curve that has turned into industrialization steps. More and more shorter well duration is born with these two initiatives, MAXIDRILL and One Phase Well. Ultimately, with the spirit of these two initiatives for bringing down well duration in gain for much better well economics has successfully set a two record breaking performance in Mahakam: 1) Being the fastest On Bottom ROP and 2) Being the fastest well ever delivered in Mahakam and Indonesia which is under two days.