What Can Deepwater Operators Do … (Part III of III)

to Help Improve Drilling Safety and Ensure Well Integrity?

This is the final segment (part three) on the recent “Effects of Water Depth Workshop” report about the effects of water depth on offshore equipment and operations. This blog is limited to a discussion of future industry needs as described in the EWD report, Technical Summary of Workshop Session #3 –Well Drilling and Completion Design and Barriers. Below, I am highlighting the last two of five future development needs under the heading B) Trends and/or Notable Technologies Envisioned for the Near- & Longterm. To download the entire report, please see part one and two of this blog.

Fourth Development Need – Managed Pressure Drilling Technologies

White Paper Comments: “A key challenge in deepwater drilling is to optimize the drilling program to reach the target interval with the desired casing size. Several managed pressure drilling (MPD) technologies are either available or under development at this time for use in subsea applications. These technologies are used to optimize the pressure profile imposed on the open hole. Using these technologies, wellbore pressures are managed in a way that preserves hole size, allowing for longer open hole intervals. Some of these technologies require the use of a high-pressure riser. Others, such as dual gradient drilling, are designed to be used with low pressure riser systems. Several of these technologies have been demonstrated or used commercially in deepwater environments.”

Regulator Comments: “MPD that uses surface choke manifold for back pressure to simulate ECD is currently not allowed for subsea BOP’s.”

Halliburton Comments:

Current regulations (see NTL No. 2008-G07) allow the use of MPD systems for drilling offshore wells with surface blowout preventers (BOP) such as those drilled by jackup rigs and rigs installed on production platforms fixed to the seabed.  These MPD systems include closed flow loop systems on the rig that along with MPD control systems and software, help improve ECD management that can improve drilling safety. Deployment of these offshore MPD systems has resulted in better drilling performance along with successful well control. Halliburton offers a MPD service and equipment for wells with surface BOPs on non-floating offshore rigs that complies with  the regulations as stated on  the GeoBalance website: “Creating only a minimal overbalanced annular pressure, Managed Pressure Drilling uses a closed-loop fluid system that avoids the regulatory restrictions on underbalanced operations while providing the benefits:

  • Faster penetration rates
  • Reduced fluid loss and reservoir influx
  • Excellent wellbore integrity.”

Industry and regulators are working together to agree on MPD systems for subsea wells that will be allowed in the regulations.  BSEE and the IADC MPD/UBO committee are discussing a NTL for floating rigs that should allow deployment on a Gulf of Mexico subsea well in less than one year.

 

Fifth Development Need – Pressure and Temperature Measurement Across Barriers

White Paper’s Comments: 7) Pressure and Temperature Measurement Across Barriers “There are several field-proven downhole data measurement and transfer technologies, commonly used in production/reservoir management applications that might be adapted to improve barrier integrity verification, testing, and monitoring in subsea wells, particularly during suspensions and abandonments. Some of these previous applications include:

  • Wired casing and pressure/temperature (P/T) for real-time monitoring of annular P/T during casing, cementing, and production operations (Cooke, SPE 19552)
  • Wireless real-time annular P/T monitoring (OTC 12155, OTC 19286, Emerson Article)
  • Fiber optic sensor measurements across producing formations (Shell primer reference)
  • Surface and downhole micro-deformation sensors for remote measurement of pressure induced abnormal flows in wells and reservoirs (SPE 138258)
  • Memory pressure gauges in liner running tools to compare actual versus simulated liner cementing pressures (SPE/IADC 79906)

Additional applications of these technologies should be investigated to enhance barrier integrity management in all phases of well construction, including drilling, suspension, completion, production, and abandonment (permanent or temporary). Opportunities exist for equipment suppliers to adapt existing technologies or to develop new

measurement and telemetry methods to deliver a suite of fit-for-purpose tools whereby the right data is measured in the right place, captured at the right time, and transferred to surface only for the time period required for the application. Potential areas for further development in support of subsea applications include:

  • Measurement and transmission of pressure data across mechanical wellbore barriers to provide independent positive and/or negative testing of barriers in series.
  • Wireless transmission of annular pressure and temperature behind casing and liner strings, during various operational phases such as casing installation and cementing, barrier verification testing, etc.
  • Advancements in measurement and data telemetry, as well as the integration of sensors, transducers, etc. with existing equipment such as bridge plugs, packers, and various casing/cementing equipment components such as seal assemblies, centralizer subs, and float equipment”

Our Comments:

Some of the above P/T measurement methods have been infrequently used in wells. These methods are not practical for use in deepwater wells with subsea wellheads. In some cases, the cost of prototype P/T sensor systems is prohibitive (eg. USD $1,000,000 for one sensor). In other cases the size of the sensor system is too large to be effectively installed in the typically small annular clearances found in deepwater wells. More research and development is needed to shrink the size of P/T sensor and data transmission systems, reduce the power requirements, and make them cost effective. However, field testing may show that the micro-deformation system’s (MDS) measurements and flow mapping capability may be very cost effective compared to other methods. MDS’s non-intrusive sensor systems can provide early warning of abnormal well and reservoir flows to allow mitigation efforts to maintain drilling safety. Micro-deformation sensors see micrometer size rock movements in all directions for very long distances (eg. surface to 15,000 ft. below) that are caused by the pressure changes resulting from leaking reservoir or other fluids. This means that leaks traveling up alongside wells, leaks between wells, and those going up or down or sideways through the caprock (aka. confining zones) around reservoirs can be detected early to allow corrective action to be implemented to mitigate them.  See more in paper SPE/CMTC 150980 titled “New Technology for Offshore CO2 Reservoir Monitoring and Flow Control” by R. Sweatman, E. Davis, E. Samson, G. McColpin, and S. Marsic; Halliburton/Pinnacle presented at the Carbon Management Technology Conference held in Orlando, Florida, USA, 7–9 February 2012.

This is part three in a series of three. Read part one here and part two here.

[toggle title=”Learn More About Ron Sweatman”]

Ron Sweatman
Chief Technical Professional – Halliburton’s Global Technical Solutions and Deepwater Team based in Houston.

Ron Sweatman has 42 years of experience in several well construction and production/injection technologies. Ron majored in Chemistry at Louisiana State University and in Petroleum Engineering at University of Louisiana, Lafayette. He has served on 20 industry committees, co-authored over 60 technical publications, received six industry awards, and invented 30 patented technologies. Ron has a broad range of oilfield-services experience, including assignments in laboratory testing, engineering design, field operations, regional management, and technical support groups. His deepwater experience started in 1978 working on the Baltimore Canyon well in 2,686 feet of water on the Atlantic Ocean Outer Continental Shelf and has continued in other offshore areas including the Gulf of Mexico, West Africa, and North Sea.

For more information, please feel free to contact me.

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