Percussion Drilling: From Lab Tests to Dynamic Modeling (2006)

Percussion Drilling: from Lab Tests to Dynamic Modeling Gang Han; Gang Han Terralog Technologies USA Inc. Search for other works by this author on: This Site Google Scholar Michael S. Bruno Michael S. Bruno Terralog Technologies USA Inc. Search for other works by this author on: This Site Google Scholar Paper presented at the International Oil & Gas Conference and Exhibition in China, Beijing, China, December 2006. Paper Number: SPE-104178-MS https://doi.org/10.2118/104178-MS Published: December 05 2006 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Han, Gang, and Michael S. Bruno. "Percussion Drilling: from Lab Tests to Dynamic Modeling." Paper presented at the International Oil & Gas Conference and Exhibition in China, Beijing, China, December 2006. doi: https://doi.org/10.2118/104178-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE International Oil and Gas Conference and Exhibition in China Search Advanced Search AbstractPercussion drilling has long been considered an effective approach to breaking rock in the civil and mining industries. A large number of air hammers were introduced to oil and gas industries in the 1980's. However, limited fundamental understandings of the physical mechanisms involved in percussion drilling hinder its acceptance and applications.In a 2-year research effort, fundamental rock physics are investigated through a series of lab tests, including single impact tests and full-scale hammer drilling tests. For each impact test, three impacts are sequentially loaded at the same rock location to investigate rock response to repetitive loadings. Besides crater depth and width, the displacement and force in the rod and the force in the rock are recorded at 100K Hz frequency. For hammer drilling tests, an industrial fluid hammer is used to drill Berea sandstone and Mancos shale under both underbalanced and overbalanced conditions. The bottom hole pressure varies from 3.5MPa to 20.7MPa while pore pressure is controlled separately, varying from 0MPa to 24.2MPa. During these tests, Rate of Penetration is recorded continuously from one pressure condition to another. Cuttings are then screened, collected, and analyzed.The lab data are then used to calibrate a 3D drilling simulator developed specifically for percussion drilling. First a strain-softening rock material model is derived from matching rock stress-strain curves in a series of rock mechanical tests. Then a stress history is specified as loading conditions based on the stress and displacement data recorded in the impact rod. With appropriate material model and boundary conditions, both rock displacement and indentation geometries are well matched. Further, the simulation reveals in detail how rock becomes defragmented when receives impact. These developments improve the fundamental understandings of rock physics involved in hammer drilling. The 3D drilling simulator can also be applied to investigate rock breakage and optimize operations in field.IntroductionInvented by the Chinese more than 4000 years ago1, percussion drilling has long been recognized to have the potential of drilling faster than conventional rotary drill, especially in some hard formations such as granite, sandstone, limestone, dolomite, etc2,3,4,5,6. With the same Weight on Bit (WOB) and Rotation per Minute (RPM), it has been demonstrated that percussive-rotary method could be 7.3 times faster than the conventional rotary method5. Air hammers have been used to drill gas wells in West Canada and Central USA since 1980s. In 1987, air hammers were tested on 27 wells in the Waterton, Jumping Pound, and Clearwater areas of Alberta, and in the Flathead valley of British Columbia. Average time to total depth for recent air drilled wells at Jumping Pound had been 80 days (best 66 days), compared to the record of 103 days drilled with mud6. In the Arkoma Basin of Central USA, a cost per foot reduction of 49% was realized with hammer bits7. Another significant advantage of air hammer drilling is less well deviation. In Ritchie county, West Virginia, there were some wells drilled into a high dipped formation, such as 45 degree. Less than 1 degree deviation was achieved for most wells, compared to 5 degree deviation with average roller cones.With challenges to drill into deep and hard rocks for hydrocarbon resources, and air hammers are limited by penetration depth and usually can not be used if formation water appears. Fluid hammers were first presented in 1990s8. Since then the industry has consistently pursued improvements in hammer design, performance, and reliability5,8.9.Despite these efforts, fundamental understandings of the physical mechanisms involved in percussion drilling remain as a significant challenge. The best ROP with acceptable economics lies more on the basis of field experience rather than a predictable way. Inconsistent overall results, risks in operation (e.g. mechanical failure), and economic uncertainties limit hammer acceptance and development. There are also confusions about the field observations that hammer drilling in shale usually poses much greater challenges than other types of rock. Simply increasing impact energy can cause cutters chipped, severe vibrations of drill string and rig structure, and even borehole collapse. Further, there are no published hammer performance data for directional wells, slim hole drilling, or coiled tubing drilling. Wide acceptance of hammer drilling may not occur until fundamental understanding of the physical mechanisms involved in percussion drilling is more clearly developed. Keywords: Reservoir Characterization, frequency, drilling operation, material model, Upstream Oil & Gas, steel rod, pore pressure, stress wave, displacement, impact test Subjects: Drill Bits, Drilling Operations, Reservoir Characterization, Reservoir geomechanics This content is only available via PDF. 2006. Society of Petroleum Engineers You can access this article if you purchase or spend a download.