Trying Something New: Using Exclusively Gyro Technology for Wellbore Surveys in Crowded Pad Drilling

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With commodity prices recovering and activity in the oil field stabilizing, the time is ripe for innovation-hungry operators to implement new technology in their projects.

When it comes to the drilling discipline, efficiencies have improved significantly based on advancements across a wide variety of bottomhole assembly (BHA) components, but wellbore surveying has been a relatively static subsection of the drilling sector until very recently. Operators are recognizing both the criticality of high-accuracy wellbore placement and the limitations of existing technology—both MWD tools and conventional mechanical gyro-while-drilling (GWD) systems—to accomplish increasingly difficult directional objectives. 

Technology

Gyrodata's Quest GWD solid-state surveying system is designed to reduce wellbore surveying time and the ellipse of uncertainty while being more reliable and efficient than comparable legacy designs. The system incorporates Gyrodata’s new solid-state SPEAR sensors, which are based on the Coriolis vibratory gyroscope technology. The sensing element is driven to oscillate at a precise frequency and amplitude, and when rotated about its input axis, a secondary motion perpendicular to the primary motion is created. The amplitude of the secondary motion is proportional to the rotation rate seen by the sensor.

The solid-state SPEAR sensors measure the earth’s rotational rate precisely and accurately at any latitude and can handle harsher downhole environments more effectively than conventional gyroscopes. The system is not affected by mass unbalance errors, which eliminates post-run calibrations, and it allows in-collar load-out, simplifying operations and tool deployment. The system’s sensor package and electronics are significantly shorter than previous offerings, enabling greater flexibility related to sensor positioning in different BHA designs and configurations.

Case study

An operator in Latin America initiated a pad-drilling campaign and wanted to ensure wellbore placement accuracy and collision risk mitigation as well as fast, efficient drilling operations without any incremental time consumption relative to MWD surveying.

With an expected 20 to 30 wells on the tightly spaced pad and a location in an environmentally sensitive area, confidence in wellbore position and trajectory was critical. The operator decided to run the solid-state Quest GWD system.

On the first well, the operator successfully ran the Quest GWD system to survey the main section of the well (200 ft to 8,000 ft), with MWD surveys taken in memory mode only down to total depth (TD) of the section as well. The system saved at least 3 hours versus running a conventional gyro system on wireline, while the extended battery life of the sensors allowed the system to be run for more than six days of operational time on the well without having to change anything out.

The Quest GWD system allowed the operator to reduce the ellipse of uncertainty by 60% (Figure 1), significantly improving wellbore placement and mitigating the risk of wellbore collision. This well was considered a proof of concept for running solid-state GWD to replace MWD for definitive surveys.

On the second well, the operator and Gyrodata were aware of downhole dynamics that required live inclination throughout the entire well, which would improve directional control and the chance of landing the well based on the drilling plan.

In addition, gamma ray LWD was requested to identify the formations, providing insight into section TD and optimized bottomhole location. The Quest GWD system was the only technology run throughout the well to TD, proving that a well could be drilled from surface to TD using only GWD with no MWD.

The system achieved similar timesaving and shock and vibration reliability results when compared to a typical MWD tool while requiring no additional time for survey transmission due to surveys at connection effectively being invisible.

The Quest GWD system provided real-time inclination throughout the well, enabling better control of the BHA through the difficult formation. Due to the inherent efficiency of the system versus conventional gyro surveying solutions and eliminating the need for individual wireline gyro runs, the operator saved 12 hours of rig time versus the original drilling plan. The integrated gamma ray measurements helped the operator accurately identify the tops and bases of the formations, allowing it to better geosteer into the production sweet spot while meeting its collision avoidance objectives.

On this well, the Quest GWD system reduced the ellipse of uncertainty by 54% versus the MWD tool. This well reinforced that solid-state GWD could replace MWD as the definitive surveying system, leading to the operator opting to implement Quest GWD on all future wells on the pad.

Moving forward

As the industry continues to face hurdles with regard to achieving sustainability and ESG targets, new ways of approaching old problems must be deeply considered. Doing things the same way they have always been done is no longer sufficient if oil and gas is to remain relevant through the coming years of energy transition.

Using exclusively gyro technology for wellbore surveys in a crowded pad-drilling operation might previously have been unheard of, but all it takes is that first operator to try something new. Believing in technology and the potential for transformative change is how the industry will improve its operational execution, financial health and environmental impact, and it is thanks to companies willing to invest in new solutions and take a risk when implementing them that the oilfield services sector will continue to move forward.