Pertamina EP recently executed an exploration drilling project in Sumatera area. The objective was to evaluate the oil reserves contained in the fractured volcanic basement reservoir zone. The very hard (26,000 psi average compressive strength, with spikes of up to 50,000 psi) and abrasive nature brought drilling challenges, in particular, how to effectively and efficiently fail and fracture the rock. In a well in the previous drilling campaign, 10 runs of bit were required to complete the 294-m interval hole section containing basement formation. Various roller cone and PDC bit designs were utilized, with a resulting maximum penetration rate capability of 1.25 m/h and maximum run interval capability of 56.44 m. Another well with a basement interval of 463 m consumed 11 bit runs with maximum run drilling interval and penetration rate of 64 m and 1.56 m/h, respectively. A conical diamond element (CDE) bit was proposed to achieve more efficient drilling in the basement. The 3D geometry of the conical diamond elements, which are placed across the bit blade, provided both a superior impact and wear resistance and concentrated point loading onto the formation; these characteristics enable the bit to cause failure and fracturing of the hard-to-drill rock more efficiently. A diamond layer in the bit is twice as thick as that of a conventional PDC cutter; this enhances impact strength and improves overall bit durability. CDE bits were implemented to penetrate the basement formation in two different wells in Sumatera area. The wells were designed as directional J-type wells with maximum inclination of 70°. In the first well, eight-bladed and seven-bladed CDE bits were run with an excellent result of 131-m and 176 m of drilling interval achieved, respectively, yielding up to 211% of drilling meterage capability improvement (compared to the previous well). The rates of penetration (ROP) generated by CDE bits were also large; up to 4.17 m/h ROP was achieved (instantaneous on-bottom ROP reached up to 20 m/h), which was equivalent to 333% improvement. In the second well, the seven-bladed CDE bit generated 230 m of drilling interval with 3.27 m/h ROP, improving the offset well performance by 259% (in terms of interval) and 109% (in terms of ROP). The CDE bit significantly saved operating time and cost by improving the drilling speed and, most importantly, eliminating unnecessary trips to change the bit. The estimated potential savings from CDE bit utilization in these two wells reached more than USD 1.1 million. The drilling optimization in Sumatera yielded insights into CDE design and features appropriate for basement application, and the engineering study behind the successful execution, actual drilling operation, and run performance comparison provided information for future such operations.
Pertamina EP is an Indonesian national oil company which subsidiaries of PT Pertamina (Persero). For nearly 60 years, the Pertamina EP drilling area has been located onshore. In September 2017, Pertamina EP successfully conducted a Poleng N-2 well as the first drilling operation in an offshore area. Originally wells candidate's Poleng N-2, proposed in early 2017 with the target of drilling operations can be carried out on TW-3 in 2017. However, considering the acceleration of production, utilities offshore rig availability and cost efficiencies, accelerated drilling operations into TW-2 in 2017. it begins with the efforts to accelerate drilling AFE approval Poleng N-2 of SKK Migas on June 15, 2017. Short preparation was conducted with the support of SKK Migas and synergy of PHE WMO and PEP as a form of Pertamina Incorporated. Synergy is done in the form Farm in contract, Material Transfer Agreement and the exchange of information and expertise of each subsidiary, as well as support for QA / QC of internal WMO competent and experienced in drilling operations using Ensco Rig 67. So in the end, in the span of about three months, can be resolved about contract services and materials, including the preparation of internal HR by chance exposure PEP Drilling wells to WMO. Poleng field located in East Java province started operated by Pertamina EP in 2013. The drilling program Poleng N-2 of the Platform CW as the first drilling operation PEP from this field is expected to increase the production of limestone reservoir targets Kujung. As for the design of drilling a sidetrack well from the well parent CW-02H, at a depth of 5,000 ft MD ± which has a horizontal well trajectory is quite challenging on the route hole the size of 6-1 / 8 ″in length ± 2500 ft. The well completion technology also comes with Inflow Control Device (ICD) and Swell Packer on 4-1 / 2 ″Liner as part of the Lower Completion. In the end the Poleng N-2 well drilling operation can be completed in November 2017, with the status: Zero incident / accident, cost about 75% of the approved budget, the percentage of Non Productive Time is less than 5% and Initial production reached 783 BOPD above target of 700 BOPD so that production acceleration can be realized with a good economic level.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.