Beauty Contest Bit : ROP Optimization with Single Run Bit in Soft Cibulakan Formation and Hard Baturaja Formation on S-Type Drilling Jatiasri Field Development

Abstract

Drilling of 9 Jatiasri wells, mostly done almost simultaneously in the year 2013-2018, recorded a valuable elaboration in the selection of a bit. Exploration wells JAS-01 to JAS-03 which have vertical well type, and JAS-04 to JAS-09 with directional S-type, require characterizing the specific selection of specific bits, especially the selection of bits on 12-1/4" section.
Drill of Cibulakan has a clay formation character, shale, sand, which more soft and difficult to steering, and occasionally result in balling in bits and Stabilizer. Also the trajectory of this section is the tangent section, which requires maintaining an extra angle of approximately 1200 meters. While Drill Baturaja (BRF) formation has the opposite character of limestone which is much harder, located at the drop section, back to vertical entering the TAF formation in the next section as the Jatiasri well interest trajectory in 8-1/2" section.
The combination of the two character formations that are united in one of these section gives formulation to bit selection characterization which can be used as a reference bit selection attribute for either vertical well type / section, tangent, build / drop section, or combination between them in 1 section with rock hardness variation in 2 different regime formations.
In the 'beauty contest' performed on 4 bits from different companies, with same feeding data, same benchmark well, in 4 wells with a relatively typical well shows interesting results. That the level of steerability, durability, stability, and ROP yield of each bit can be taken into consideration of bit selection to achieve optimal and efficient drilling target.