Real-Time Advisory System Mitigates Drilling Vibrations in a Lateral Section
Authors: Wilson Adam 
Published: October 2018

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 188942, “Mitigating Drilling Vibrations in a Lateral Section Using a Real-Time Advisory System,” by J.R. Bailey, SPE, and G.S. Payette, SPE, ExxonMobil; M.T. Prim, J. Molster, and A.W. Al Mheiri, Zakum Development; P.G. McCormack, SPE, Halliburton; and K. LeRoy, Pason Systems, prepared for the 2017 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 13–16 November. The paper has not been peer reviewed.

A real-time drilling-data analysis and recommendation system that leverages surface drilling data was deployed in a lateral section of a well from an artificial island in Abu Dhabi. A key objective of this technology was to provide the driller with an easy-to-use display of a novel drilling-performance map. This paper presents data from the demonstration run, illustrates the features of this technology, and provides general observations on optimization of drilling parameters in this hole section.

Background

A research prototype drilling advisory system (DAS) was set up on an island rig with a wellsite information transfer specification (WITS) data feed from the mud-logger cabin over a fiber-to-serial cable to the computer in the driller’s cabin.

The DAS helps the driller make decisions for managing controllable drilling parameters to enable a high rate of penetration (ROP) and low vibrations. The system uses surface data only (i.e., data obtained from sensors instrumented on surface equipment) from the mud logger. The platform then analyzes the data and displays basic surveillance information, including heat maps that vary with the controllable drilling parameters. On the basis of this data and processing algorithms, the system makes recommendations for the controllable parameter values.

Data from three intervals were analyzed, and two of the three saw contrasting trends of stick/slip [torsional severity estimate (TSE)] and mechanical specific energy (MSE) with increasing rotary speed, whereas one interval did not see such a tradeoff. The complex interplay between these dysfunctions requires an application-specific real-time advisory system to provide optimal drilling performance.

The control variables for this drilling application were ROP and rotary speed.

Intervals for Data Analysis

The 8½-in. drilling interval started from the 9 5/8-in. casing shoe at 13,916 ft, and section total depth was called at 23,974 ft. Drilling data from this interval was subdivided into seven intervals corresponding to drilling tests, with parameter recommendations from the DAS analysis.

Examples of Drilling-Parameter Optimization

To initiate the DAS, the driller conducts a drilling test by starting the calibration mode on the advisory system to reset the system memory. Parameter set-point values then must be maintained relatively constant for a time sufficient to determine good average values for the drilling response. The advisory system requires a statistically significant sampling of data at stationary parameter values. When several such calibration points have been recorded, the system then provides automated analysis of the drilling test for the span of operating parameters. If the formation changes over this interval substantially, the calibration process should be repeated.