A New Friction Reduction Tool with Axial Oscillation Increases Drilling Performance: Field-Testing with Multiple Vibration Sensors in One Drill String

Abstract

Weight transfer problems, hanging-up, poor toolface control and diminishing ROP are all problems that are encountered with steerable motors in high angle and horizontal wells. A number of oscillation devices have been introduced to the market over the years to aid these common problems. Both axial and lateral vibration tools have proven to provide improvements to drilling performance and toolface control. However, as with any device, there are always limiting factors, and oscillation devices could cause unwanted vibrations that interfere with measurement-while-drilling (MWD) systems and even cause component failures. This paper describes the operation and field-test results from a new axial oscillation tool. The tool uses a mud valve to generate pressure pulses in the string. These pressure pulses are magnified using a specifically designed stroke tool referred to as an amplifier. The mud valve is driven with a short power section from a Positive Displacement Motor (PDM). The lobe configuration of the power section is directly related to the frequency of the tool, while nozzles in the tool allow for variable pressure regimes of differing applications. The system was tested with specific MWD systems in a flow loop prior to the job to confirm compatibility. Key components in the string were instrumented to gather critical information on vibration frequency levels throughout the BHA in an effort to optimize system performance. A compact, self-contained 3-axis inclinometers and 3-axis shock sensors (¾-in diameter and 3.8-in length) have been deployed during field testing to capture downhole dynamics. These sensors were strategically positioned in the BHA to gain understanding of vibration propagation distance/pattern and vibration frequency changes over the course of the run. Downhole instrumented sensors were used to confirm the value of the axial vibration mechanism. The use of multiple compact downhole dynamics recording devices has provided new insights in challenging steerable motor drilling applications, assisted with an axial friction reduction tool.

A Review of the Research and Development of High‐Frequency Measurement Technologies Used for Nonlinear Dynamics of Drillstring

“…Both VOTs and LATs could have negative impact on reliability of electronic and mud pulse equipment results in nonproductive time tripping for failed equipment due to the fact that oscillations and vibrations are being introduced to the BHA and drill string. A new axial FRT was developed by Jones et al [60], and the high-frequency burst data showed that no excessive shock and vibration were being induced into the BHA and string from the FRT, presented that the FRT was effective in transmitting axial oscillations along the BHA without introducing any damaging effects to the BHA.…”