BACKGROUND

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present embodiments. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

Directional drilling is commonly used to drill non-vertical wellbores. For example, a directional drilling operation may be conducted when the target pay zone cannot be reached from a land site vertically above it. In order to form such wells, a direction drilling system is used. One example of a direction drilling system is a point-the-bit rotary steerable drilling system, in which the direction of the bit is changed by bending the shaft running through it, thereby changing the drilling direction. The tilt angle of the bit is often referred to as the toolface angle, which is described in further detail below with reference toFIG. 1B.

A rotary steerable system requires various control inputs or settings to control the system behavior and drilling operation. Generally, the more accurately the drilling system is controlled, the better it performs, ultimately leading to a more successful drilling operation.

As the rotary steerable system drills a wellbore, it exhibits a number of outputs and states, such as flow rate, turbine speed, turbine acceleration, rate of change of toolface, disturbances among others. The more data that is collected regarding such outputs and states, the more finely the drilling system can be controlled. Typically, in order to obtain measurements of certain such states, the drilling system needs to be instrumented with a host of sensing devices to take the respective measurements. However, due to cost-benefit constraints, space constraints, performance and reliability constraints, among others, it may not be feasible or practical it to implement such sensing devices in the rotary steerable system. Thus, important data which may improve the effectiveness of a drilling operation are not measured or logged. As such, there remains a need for a solution which provides insight into such states of a rotary steerable system without requiring the implementation of sensing devices.

