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.

The Louise (LSE) is one of the primary oil-producing fields in the Pertamina EP Asset V. This area has an issue with high potential of total losses in the top section [~400 m measured depth (MD)], which causes an inability to set the 13.375-in. casing at the required depth. As a result, this problematic zone must be drilled conventionally in two different sections, 17.5 in. and 12 .25 in., whilst combating losses. Pertamina EP spent up to 10 days as nonproductive time (NPT) to combat losses, resulting in high investment cost. A new innovative method was required to face this challenge with the objective of drilling deeper through the loss zone in a single run in a more effective and efficient and a safer way. Nondirectional casing drilling technology was introduced to solve this problem. The casing drilling system simultaneously drills and runs the casing through the lost circulation zone in a single run, which provides a more efficient and a safer operation. Its plastering effect helps strengthen the wellbore by smearing cuttings into the wellbore wall, sealing pores in the formation to reduce fluid loss. At the same time, it saves the rig operating days by eliminating the loss-combating days and the dedicated casing run. The key driver of this technology is the drillable alloy casing bit specially made for drilling vertical or tangential wells, which can be drilled out by any standard PDC or milled tooth after it has drilled to total depth (TD) and the casing has been cemented in place. On the pilot casing drilling project well, this system successfully drilled 351.25 m of 13.375-in. × 17.5-in. section to the casing point in a single run passing through the problematic loss zone. The 13.375-in. casing was cemented in place, and the casing bit was successfully drilled out using a conventional 12.25-in. PDC bit. Compared to the conventionally drilled offset wells, this technology enabled up to 220 m deeper 13.375-in. casing setting depth, which consequently eliminated the necessity of loss-combating activity in the 12.25-in. hole section. The implementation of the casing drilling system solved the lost circulation problem and provided an additional benefit of eliminating a dedicated casing run. The casing drilling technology helped Pertamina EP to reduce the well drilling time by up to 4.75 operating days, saved up to USD 555,913 of drilling cost, and achieved 50 m deeper well TD compared to the plan. The pre-execution engineering work was one of the key activities leading to the success.

Well M is a vertical shale gas exploration well in Indonesia. The presence of overpressured shale formation dictated the requirement to have a 16-in. intermediate casing string between the 20-in. and 13.375-in. casing to cover an approximately 350- to 1000-m measured depth (MD) interval. The mandatory logging operation in all hole sections required a 12.25-in. pilot hole to be predrilled, to enable the logging tool to get a good measurement quality, before it was enlarged to 17.5 in. for setting the 13.375-in. casing. Several hole opening challenges needed to be considered in this operation: 1) The hole opening tool should pass the 16-in. casing inside diameter (ID) restriction (14.936 in.); 2) the tool needed to be applicable for hole opening with an existing pilot hole (bi-center is not a feasible option); 3) the tool should be able to open the shoe track from 12.25 in. to 17.5 in. for 13.375-in. casing run assurance; and 4) the hole opening needs to be as efficient as possible to eliminate multiple runs. A dual hydraulically expandable underreamer was proposed to answer all those challenges. The configuration consists of two underreamers with different opening capability, which satisfies the high-ratio opening requirement. The lower reamer opened the hole from 12.25 in. to 14.75 in., and the upper reamer further opened the hole from 14.75 in. to 17.5 in. Because running a tandem underreamer is not a common operation, a thorough vibration analysis must be performed to ensure the tool reams in a stable condition, not only to avoid downhole tool failure but also to produce a smooth borehole. Hydraulics optimization is also critical to ensure both underreamer cutter blocks are fully opened during the run. The tandem underreamer successfully opened the hole from 12.25 in. to 17.5 in. in one run to the section TD from 980 to 1623 m MD (a 643-m interval). At the surface, both underreamer cutter blocks were still in a good condition with 0-0-NO cutter dull and in gauge condition, which showed a good stability. This is also supported by the success of the 13.375-in. casing run to bottom without any issue, indicating a good and smooth borehole. The tandem underreamer method successfully achieved the high-ratio hole opening objective and saved drilling time by eliminating the unnecessary trip for having two separate underreaming runs. The underreamer tool mechanism and the criteria by which the dual underreamer configuration became the solution to the main challenges in this case study were documented. The study showed that the prejob engineering work (vibration modeling using dynamic finite element analysis and hydraulics modeling) was a critical part in the success of the operation.

Objectives/Scope: Reports from a NOC under Production Sharing Contract with SKK Migas show that MDT success ratio conducted is only 40 -50% between years 2012 to 2013. High frequency of failures happened in 12 ¼Љ hole. The objectives of the research are to find out source of the problem and the solution. The scope of the research is MDT procedure conducted in years 2012 -2013. Methods, Procedures, Process: Research starts with investigation of years 2012 to 2013 MDT failures. The results then categorized as equipment and tools related, procedures related, and human error.The results show most of failures root-caused by insufficient procedure. Further investigation using interview with engineers and reports examining conducted on the existing procedure. Investigation shows the NOC not conducting proper management of change process to include MDT procedure since they believe existing procedure is adequate for additional MDT work. The research then exercises new drilling procedure using management of change and lean sigma approach. New drilling and MDT procedure then applied to year 2014 campaign.Results, Observations, Conclusions: In late 2013, SKK Migas enforced the NOC to apply proper drilling procedure for MDT. The NOC used management of change and lean sigma process to design new procedure and included any additional works required. The NOC also used heuristic approach to adapt the lithology character of subsurface formations and aquifers specifically since there was coal layer beneath. The NOC also considered any lesson learn from adjacent well and field. Drilling campaign in 2014 for the field consists of 10 drilling with MDT. New procedure was applied and close monitoring was performed. Nine of ten drilling works with MDT were successfully performed without major incidents. The wells are still producing and showing good production performance. The NOC also successfully uses MDT results from nine wells to predict field performance and planning 2015 drilling campaign.Novel/Additive Information: Management tools such as management of change process and lean sigma has been applied in many fields of work nowadays. The practices assure that any additional works or changes will be adopted properly and in a new and lean procedure or design. This paper shows radical success ratio increase when those management tools are applied especially for traditional-fashioned NOCs.

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.