Publications

K-field, a mature field in the Central Sumatra Basin that has been producing since 1971, has oil potential in the TG_2 sand, which had not been produced from the field’s development until 2000. Since 2000, hydraulic fracturing has been done in TG_2 sand, which is classified as low-quality. Hydraulic fracturing was done in directional wells up until 2023 and was shown to boost oil production by about 120 barrels per day per well.

The application of hydraulic fracturing has expanded to include horizontal wells, particularly in the lateral section where the pay zone is located. Multi-stage fracturing (MSF) is the process of hydraulic fracturing in lateral sections that can be carried out in multiple stages along the pay zone to increase oil gain. This might be a technological advance that opens up mature fields’ oil potential. A distinctive well architecture was applied for the first MSF horizontal well in K-field to enable MSF along its lateral section.

The design selection process for this MSF well is explained in this paper. A backward design method is used, starting from the main objectives that need to be met, for instance proper zonal isolation between stages, accurate placement of plugs in the lateral section, plug milling techniques to reduce formation damage in depleted reservoirs, a large entrance hole diameter, good hole cleaning during plug milling, and finally, well architecture can be selected based on these goals.

The optimal approach for each goal is determined by considering four key drivers: technical features, operational complexity, hydraulic, and material lead time due to the project timeline. At least one primary driver from each target serves as the basis for determining which approach is most appropriate to employ in this situation. Top risk assessment of multi-stage fracturing execution will also be discussed in this paper to enhance safety during execution.