Use of Gyro-MWD Technology Offshore, a Step ... - Saudi Aramco

Use of Gyro-MWD Technology Offshore, a 

Step Change in Drilling Performance in Saudi 

Aramco 

Authors: Bashaar A. Al-Idi, Hasan F. Al-Sarrani, Jeff Stewart, Abhijeet Sarka and Geoff Smith 

ABSTRACT 

Over the past few years, Saudi Aramco has achieved major 

efficiency improvements while drilling and completing smaller 

diameter hole sections. Such improvements provided sig - 

nificant reductions in rig time, and consequently reduced the 

overall operational cost. Less attention was paid to the upper 

hole sections due to less exposure to third party rental tools 

used in them. Offshore oil wells in Saudi Arabia recently 

experienced major savings in the 28”/22” hole section after 

the successful utilization of the new gyro measurement while 

drilling (Gyro-MWD) technology coupled with powerful 

performance drilling mud motors. 

The normal process was to drill the 22” hole section, of 

+/- 1,050 ft, by running gyro single-shot surveys every 50 ft - 

100 ft drilled until the well was in a safe path away from 

other wells within its vicinity. After adopting the Gyro-MWD 

system, along with a modified 22” bit and 11¼” performance 

mud motor, the rate of penetration (ROP) increased by 82%, 

thereby reducing the cost per foot. 

The increase in the ROP resulted in an average savings of 

0.9 days per well (6 to 12 wells per platform) at this stage of 

drilling. In addition, the reliability of the gyro tool face from 

vertical, even when inside the casing, provided confidence in 

drilling operations, which facilitated an increase of the weight 

on bit (WOB) leading to faster drilling, thereby improving the 

overall ROP. Furthermore, eliminating the use of a wireline to 

run surveys increased the safety of the operation. 

The success of these 22” hole sections was substantial across 

the board, since it was one of the challenging areas where major 

improvements had not taken place before in several years. 

This article will evaluate the new drilling practice in more 

detail. It will also cover the conventional drilling and 

operational practices, and the thorough planning stages that 

resulted in these fruitful savings. 

Nevertheless, with the recent surge in oil prices and drilling 

operations, coupled with the limited supply of rigs worldwide, 

it has caused rig rates to increase exponentially. All operating 

companies are now looking to improve operation time and 

reduce nonproductive time to optimize drilling. 

BACKGROUND 

Saudi Aramco’s increased offshore drilling activities have given 

rise to collision concerns. Offshore fields in the Kingdom are 

congested, and new wells on the platform are planned within 

close proximity of existing wells. Therefore, it has become 

essential to practice good wellbore placement and management. 

Historically, multi-well platform directional drilling has 

presented unique challenges, especially in the initial drilling 

phase. New wells must be carefully navigated around existing 

wells and eventually steered clear of all magnetic interference 

to the desired target. Figure 1 shows the well spacing between 

each well on an offshore platform. 

Because of the proximity of other wells, it is impossible to 

use any magnetic based survey system in the top hole part of 

the well. Therefore, gyro survey tools are normally used to 

give the directional driller the azimuth and tool face data 

required to orient the motor and steer it through this interval. 

INTRODUCTION 

Gyro measurement while drilling (Gyro-MWD) technology 

was first introduced and utilized in early 2001 to replace the 

gyro single-shot survey system for certain applications. Due to 

the high equipment cost at the time, the Gyro-MWD 

technology was not economical to run and the gyro singleshot 

survey still dominated the market. 

Fig. 1. Well spacing and layout of offshore platform. 

12 WINTER 2010 SAUDI ARAMCO JOURNAL OF TECHNOLOGY

GYRO SINGLE-SHOT SURVEY 

Gyro single-shot orientation tools, Fig. 2, are typically run on 

the wireline into the well; the tool is seated above the motor or 

a standard MWD system in an orienting sub to provide 

orientation data. Normally, the gyro single-shot orientation 

tool is run every 50 ft to 100 ft. This continues until the 

wellbore clears the magnetic interference, which can take up to 

10 or more runs during a complex kick off. Run time usually 

averages 30 to 60 minutes per run, depending on depth. This is 

in addition to the 30 minute average circulating time that it 

takes to clean the hole prior to holding the string still and 

running in with a wireline and the gyro single-shot tools. 

GYRO-MWD TECHNOLOGY 

The Gyro-MWD, Fig. 3, was developed so that the directional 

driller could benefit from having the gyro sensor as close to the 

bit as possible and have the ability to get fast gyro orientation 

survey data real-time in minutes rather than the average 30 to 

Fig. 2. Gyro single-shot survey tool. 

Fig. 3. Gyro-MWD tool. 

SAUDI ARAMCO JOURNAL OF TECHNOLOGY WINTER 2010 13

60 minutes in the gyro single-shot survey case, saving 

considerable rig time. The Gyro-MWD tool face in real-time, 

while full survey data can be pumped to the surface after 

3 minutes still time. Both gyro and magnetic readings can be 

obtained, which can clearly indicate the clearance from any 

magnetic interference existing in the wellbore. 

GYRO-MWD SYSTEM VS. GYRO SINGLE-SHOT 

SURVEY 

As the Gyro-MWD technology emerged, it was essential to 

understand what this technology can bring that makes it more 

competitive and what the main applications are where it would 

have advantages over the gyro single-shot survey. The best way 

to introduce this technology is by taking an in-depth look at 

the nature of both systems. A recent evaluation of each survey 

tool was conducted in five main categories: safety, wellbore 

geometry, rate of penetration (ROP), time savings and other 

applications. 

SAFETY 

Safety of the platform, wells, rigs and the people operating on 

the platform is without doubt the one concern that no one can 

ignore. Gyro-MWD facilitates a much safer operation over the 

conventional wireline gyro single-shot survey system. The gyro 

single-shot survey necessitates wireline operations, which in 

turn requires additional personnel and equipment on the rig, 

including a wireline unit and the tools that operate with it. 

The rigging up and rigging down for wireline operations can 

sometimes be dangerous as many incidents on the rig are 

associated with wireline operations. 

Another area of safety where Gyro-MWD has a major 

advantage over the conventional gyro single-shot survey is the 

avoidance of collisions. This new technology drastically 

reduces the chance of a collision with existing wells in the 

platform, and enables drillers to achieve an accurate and 

smooth wellbore adhering closely to the well plan due to the 

continuous survey information being obtained while drilling. 

The directional driller does not have to drill 50 ft or so to get 

a survey. The Gyro-MWD system is placed directly above the 

motor in the bottom-hole assembly (BHA), which is 

approximately 40 ft away from the bit. In contrast, the 

conventional wireline gyro single-shot system is placed on a 

universal borehole orientation (UBHO) sub above an MWD 

tool, taking it 70 ft more or less away from the bit, leading to 

less accuracy of reading and bit projection compared to the 

Gyro-MWD technology. 

WELLBORE GEOMETRY 

Gyro-MWD technology also provides a better wellbore 

geometer as the directional driller is not drilling 50 ft to 100 ft 

“blind” as in the case of the gyro single-shot survey. The realtime 

inclination and azimuthal readings result in drilling a 

smoother wellbore profile with no unexpected left/right turns 

or severe doglegs, Fig. 4. 

Fig. 4. Spider plot of a surface section planned vs. the section actually drilled using Gyro-MWD technology on a 10 well platform. 


Fig. 5. Spider plot of a surface section planned vs. the section actually drilled using a wireline gyro single-shot survey. 

The smoother well profile obtained by utilizing the Gyro- 

MWD technology reduces problems in running casing freely 

to the bottom, with more joints per hour being run. The 

smoother profile with Gyro-MWD is evident when compared 

to wells drilled with a conventional gyro single-shot system, 

Fig. 5. 

RATE OF PENETRATION 

The gyro single-shot survey requires stopping and circulating 

at regular intervals prior to running the gyro in hole to obtain 

survey information. In these conventional operations, it is 

essential to control the weight on bit (WOB) to avoid 

excessive torque from the motor so that the wellbore does not 

deviate un knowingly from the planned direction, thereby 

limiting the optimum ROP that can be achieved. 

With the Gyro-MWD system’s ability to pump up 

continuous survey data, these limitations are eradicated. 

TIME SAVINGS 

The Gyro-MWD technology has significantly contributed to 

increased rig time savings. These savings are attributed to: 

• High ROP performance. 

• Negligible time spent obtaining surveys. 

• Elimination of standby time between connections. 

• Less time needed for reaming the hole and circulating. 

• Faster times for running casing and tripping in/out of 

hole. 

OTHER APPLICATIONS 

Other applications for running the Gyro-MWD technology, 

where the economics are better, include orienting and setting 

whipstocks for sidetracking wells where regular MWD tools 

are affected due to magnetic interference. 

CONCLUSION 

The initiative to utilize the Gyro-MWD technology produced 

expected results. Gyro-MWD proved not only to be efficient, 

but also to be beneficial in increasing the ROP performance 

and improving the wellbore geometry. Also, the Gyro-MWD 

system proved to be a much safer piece of equipment to 

operate for both the wells on the platform and the 

simultaneous operations on the rig. It eliminated the need for 

any wireline equipment, extra personnel and riging up/down 

wireline operations. As a result of less standby time for 

surveys, the Gyro-MWD technology clearly achieved a smooth 

penetrated hole. In conclusion, Gyro-MWD met Saudi 

Aramco’s goal and objectives to reduce rig time and optimize 

operations in Saudi Arabia offshore fields. 

ACKNOWLEDGMENTS 

The authors would like to thank the management of Saudi 

Aramco for permission to publish this article. Also, the 

authors wish to thank the Saudi Aramco Offshore Drilling 

Department, Halliburton Sperry Drilling and Scientific 

Drilling for actively supporting this work and granting 

permission to publish this article. 

SAUDI ARAMCO JOURNAL OF TECHNOLOGY WINTER 2010 15

BIOGRAPHIES 

Bashaar A. Al-Idi has been with Saudi 

Aramco since 1998. He worked in 

various operational field assignments 

before being appointed a Drilling 

Foreman in 2005. In 2009, Bashaar 

moved to the Offshore Engineering 

division to work as an Offshore 

Drilling Engineer. 

He received his B.S. degree in Mechanical Engineering 

from Vanderbilt University, Nashville, TN. 

Bashaar is a current member of the Society of Petroleum 

Engineers (SPE). 

Hasan F. Al-Sarrani joined Saudi 

Aramco in 1997, working as a Drilling 

Engineer for both onshore and 

offshore operations. In 2008, he 

became acting Supervisor for the 

Offshore Exploration Drilling 

Department, and then in 2010, Hasan 

became an Offshore Drilling Supervisor. 

Jeff Stewart has been working for 

Sperry Drilling since 1998. He began 

working in 1978 in the offshore 

drilling industry in various positions, 

ultimately as a Night Tool Pusher. Jeff 

has worked in the field, principally in 

Saudi Arabia and previously in Oman. 

He is currently a Directional Drilling Coordinator with the 

primary responsibility for offshore operations with Saudi 

Aramco. 

Abhijeet Sarkar works for Scientific 

Drilling Controls Co. Ltd. in the 

Business Development Department 

where he is responsible for enhancing 

revenues within the region by 

evaluating new business opportunities 

and targeting new clientele. 

Abhijeet has 4 years of experience in the oil field 

industry. In the early part of his career, he was assigned as 

a Field Engineer to run conventional gyro services in the 

Saudi Arabia district. 

Abhijeet received his B.S. degree in Administrative 

Studies from York University, Toronto, Canada, and his 

M.S. degree in International Business from the University 

of Wollongong, Dubai, U.A.E. 

Geoff Smith is Head of Operations for 

Scientific Drilling Controls Co. Ltd. in 

Saudi Arabia. He has over 30 years of 

experience in the oil field industry, 

working in the Middle East, North Sea 

and Far East. Geoff has vast 

knowledge of the directional surveying 

industry and is currently managing operations for the Saudi 

Arabia and Bahrain districts. 

Geoff studied Mechanical Engineering in the U.K. and 

first joined Sperry Sun Middle East in 1976.

Use of Gyro-MWD Technology Offshore, a Step ... - Saudi Aramco

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