Role of Wellbore Imaging and Specific Mineralogy Inputs Data in Bit Selection and Design Softwares

Abstract

Formation drillability is one of the most important aspects for planning and designing a new oil/gas well since the factors affecting the drilling performance have complex relationships between formation properties, drill bit design and operational parameters. In view of the high operating cost of drilling rigs, if Rate of Penetration (ROP) can be enhanced, it will reduce open-hole formation exposure time and complications associated with it, resulting in significant savings in drilling time and cost can be realized. Normally bit engineers utilize the assumed lithology from mud logs and detailed depth-wise lithology of offset wells. The lithology can also be interpreted from conventional logging data such as Sonic, Gamma and Density. Furthermore, the rock's compressive strength is calculated using Compressional / Shear travel time (Sonic log), Bulk density (Density log) and Shale content (Gamma log). These utilized tools to detect the lithology and rock mechanical properties have an extent of uncertainty due to effects either related to the borehole or drilling fluids that require extensive corrections. That degree of uncertainty subsequently can affect the drill bit design criteria, selection and viability of performance-enhancing features. This present paper reveals a new practical approach as a solution to minimize uncertainty in terms of bit design and selection by utilizing wellbore imaging either LWD and/or Wireline borehole images and lithology & mineralogy from either wireline mineralogy logs "Pulsed Neutron" and/or ROQSACN instrument to precisely deliver an accurate input data to the drill bit design/selection software modules.

A Novel Application of Ensemble Methods with Data Resampling Techniques for Drill Bit Selection in the Oil and Gas Industry

“…Further, they estimated the compressive index of rock formations along with lithological data which were then utilized by a Drill Bit Optimization System to help the driller for drill bit selection [13]. Sherbeny et al [14] used wellbore images and mineralogy logs for the selection and design of drill bits. Mardiana and Noviasta [15] combined rock strength analysis and finite element modeling for the selection of drill bits.…”

“…G-mean = √ TP rate .TN rate (14) where TP rate is the true positive rate and TN rate is the true negative rate. Both of these parameters are expected to be high concurrently for good classification results.…”

Drill Bit Selection in a Formation With Different Sedimentary Facies Using the Markov Chain: A Case Study at One of the Oil Fields in the South of Iran

“…In these layers, low revolutions per minute (RPM) and high weight on bit (WOB) should be applied to reduce bit erosion. Furthermore, the proper rockbreaking mechanism in such a formation is crushing and scraping (Sherbeny et al, 2016;Akisanmi, 2016;Strasburger et al, 2019). Thereby, the implementation of a PDC bit (M223) in these cases causes severe erosion 2 Polycrystalline Diamond Compact of the bit and low drilling speed and consequently, leads the bit to be stuck or lost.…”

Analysis of Cuttings’ Minerals for Multistage Hydraulic Fracturing Optimization in Volcanic Rocks

“…The application of elemental-mineral transformation analysis is a comprehensive technology used in geology. − The rock cutting analysis technology (RoqScan cuttings’ analysis system) , that is based on elemental-mineral transformation has been proposed by the CGG company from the United States. This technology provides the possibility of analysis while drilling. − Using this technology, field tests have been successfully implemented in various oil fields around the world, such as Bakken Shale, , Barnett Shale, Haynesville Shale in Northwest Louisiana, Southern Powder River Basin in Wyoming, Marcellus Shale, and Cauvery Basin in Southern India …”