PDC Bit Parameters Optimization
First, What Parameters Affecting Drilling With PDC Bit
Optimum Hydraulic Range
PDC Drilling Parameter “PDC Bit Rotary speeds”
PDC Drilling Parameter “Weight On Bit”
Lighter weight-on-bit means lower stress on the drill string, with increased string life as a result. There’s less drag in directional holes because fewer drill collars are required, reducing the potential for stuck pipe.
Oil & Water Base Mud & PDC Bit Parameters
These bits have made economical runs in both oil and Water Based Mud. Oil base muds and the addition of lubricants to water base muds will enhance PDC bit performance in formations that tend to be somewhat plastic and sticky.
Try To Avoid These Formations While Drilling With PDC Bit
Formations which should be avoided with PDC bits are soft sticky shales and clays, abrasive sands, and those formations which are very hard. In sticky formations, PDC bits have a tendency to ball up; in abrasive formations or hard formations, cutter wear and breakage occur rapidly.
PDC bits cost (check also drilling cost per foot) savings are measured in terms of tripping pipe time saved, longer bit life, improved rates of penetration, and fewer rig hours required to drill a well.
Now, Let’s Move To PDC Bit Drilling Parameters & Precautions
Even though PDC bits have achieved recognition as a viable tool for improved drilling, certain precautions and drilling parameters should be met in order that the bit run be as efficient and economical as possible.
- When the prior bit is removed, it should be inspected for any damage. If junk was left in the hole, do not run a PDC bit until the hole is cleaned.
- When removing the bit from its box, handle it carefully. Do not roll it out on the rig floor. If the bit is dumped on the floor and some of the cutters are chipped, the bits life will be reduced.
- The interior of the bit should be inspected to make sure no debris is left inside.
- The proper bit breaker should be used to make up the bit.
- The bit is one solid piece and does not have the limited flexibility of roller cone bits. Hitting ledges or running through tight spots can damage the gauge cutters.
PDC Bit Drilling Parameters While Reaming In Hole
PDC Bit Drilling Parameters While near bottom
When Drill String become near bottom, the last joint should be washed down slowly at full flow and 40-50 rpm, to avoid plugging the bit with any fill. To locate the bottom of the hole, observe the Torque and weight indicators. Because of the type of cutting structure on PDC bits, it is common that the first on-bottom drilling parameter is a sudden increase in torque.
PDC Bit Drilling Parameters While Drilling
- In soft formations, the bit will drill quickly with light parameters (light weight, and the rotary speed) then should be increased until the bit is drilling at its fastest rate (usually between 100-150 rpm).
- In hard formations, it will take much longer to drill the one foot. Adding weight too quickly will damage the cutters. Once the bottom hole pattern is established and weight is added, watch the Torque indicator for possible problems.
There is no limit to rotary speed, use as much as possible without damaging the rest of the Drill String.
How To Know From PDC Drilling Parameters That PDC Is Not Suitable
What Precaution To Consider After Making Connection
PDC Bit Drilling Parameters & Formation Change
How PDC Drilling Parameters Tell You That Your PDC Is Weared
Useful Papers Related To PDC Bit Drilling Parameters
Investigation of Various ROP Models and Optimization of Drilling Parameters for PDC and Roller-cone Bits in Shadegan Oil Field
According to the field data, there are several methods to reduce the drilling cost of future wells. One of these methods is the optimization of drilling parameters to obtain the maximum rate of penetration (ROP) in each bit run. Many parameters affect ROP like hole cleaning (including drillstring rotation speed (N), weight on bit (WOB), floundering phenomena, mud rheology), tooth wear, formation hardness (including depth and kind of formation), differential pressure (including mud weight (MW)), etc
The most effective approach to reduce the cost of drilling oil and gas wells is to increase penetration rate. To reduce well construction costs substantially, drilling time must be reduced. Major reductions of time spent in other activities or categories would not have an overall impact as significant as reducing drilling time due to increase in ROP. Several approaches can be considered for reducing total drilling time; however, the most effective way is to improve drilling efficiency. Moreover, an increase in rate of penetration (ROP) must be accompanied by equal (or greater) equipment reliability so that overall trip time is maintained ………
Technology Update: Aggressive Drilling Parameters, PDC-Bit Innovations Cut Run Times in Abrasive Oklahoma Granite Wash
A combination of new drill-bit technology and new operational practices has enabled operator Marathon Oil to use polycrystalline-diamond-compact (PDC) drill bits, and reduce drilling time by 24%, on wells in a part of the Anadarko basin where abrasive conditions at shallow depths previously have required the use of roller-cone bits