Selecting Optimum Drilling Parameters by Incorporating Vibration and Drilling Efficiency Models

Abstract

To avoid severe vibrations, different drillstem (or drillstring) vibration models have been used to predict and avoid resonance regions by selecting bottom hole assembly (BHA) components and operating parameters such as weight on bit (WOB) and RPM. The overall efficiency of the drilling operations can be evaluated using either a mechanical specific energy model or an inverted rate of penetration (ROP) model. The key output from the analysis described herein is a method to improve drilling efficiency by incorporating a drillstem vibration model with an ROP model. A data set including vibrational data was collected from a section of a well drilled in the North Sea to analyze the level of drilling efficiency for the drilled section. A drillstem vibration model was created using nonlinear finite strain theory, including coupled axial, torsional and lateral vibration modes. To optimize the drilling process, the vibration model was integrated with an ROP model. The vibration model calculates the critical speeds for a given BHA at a given depth, supplied with an operational window for WOB and RPM combinations that gives the optimal combination in therms of ROP. By analyzing the drilling variables such as WOB, rotational speed, and ROP, the drilling operational effectiveness was evaluated. The operational window with low vibration level and with the potential maximum instantaneous ROP was chosen to be the optimum drilling scenario for the target hole section. The model was verified with the analysis of the collected field data where the level of drilling efficiency was obtained for the different sections drilled. This paper presents a new methodology to increase drilling performance by means of drillstem vibration and ROP modeling.

Selection of Suitable Drilling Parameters for obtaining high Rate of Penetration in Majnoon Oilfield

“…It is generally known that time is money and improving the ROP will reduce the cost of the well, the major factors that affect the drilling time and costs are bit type, mud type, WOB, RPM and flow rate, therefore the primary criteria of drilling optimization is an economical approach resulted in optimization based on the correct selection of WOB, RPM, and bit types which produce the highest ROP and consequently the minimum cost of drilling [2].…”

The vibration harmonic response analysis of drillstring in compound drilling

“…High-quality borehole is crucial to hydrogen energy storage or oil & gas development, while compound drilling plays an important role in improving borehole quality [1][2][3]. Drill bit and stratum contact with each other in drilling, which, however, will generate exciting vibration on drillstring [1].…”

“…It can cause local stress concentration of drillstring, and even damage drillstring if circumstance is serious; consequently, drillstring will be broken, downhole accident may occur and drill cost will be increased. Bit bouncing, stick slip, vortex motion and impact are key research objects [2][3]. Lateral impact of drillstring not only harms drillstring but also lowers wellbore quality greatly.…”

The vibration modal characteristics of drillstring in compound drilling

“…The compound drilling is benefit for the wellbore quality improving. As an unfavorable factor for drilling construction, violent drillstring vibration usually causes drilling tool failure [1][2][3][4][5][6]. During compound drilling process, drilling bit is driven by turntable and positive displacement motor (PDM).…”