Oil and Gas

Standardization and modularity to drive operations efficiency

Mitigate the financial risk of ordering back-up float equipment

By Amy Farrar December 2, 2020
Courtesy: Frank’s International

Oil & gas operators look for opportunities to make operations more efficient by standardizing casing accessory designs, and thus standardizing the accessories that attach or make up the casing. However, this proves difficult when well requirements and casing availability dictate what combination of casing weights, grades, and connections are used to construct a well. Along with the variations in casing, operators are compelled to make use of casing accessories that are customized to their casing requirements. It can be challenging to use this equipment across multiple wellbores.

Reducing the costs associated with casing accessory inventory is also a major initiative for many industry operators. This focus on cost containment extends to the practice of keeping customized casing accessories on consignment. A consignment arrangement allows the operator to have casing accessories available as needed without having to maintain and hold backup or contingency inventory. This inventory can sit unused for years after a drilling campaign since casing programs change based on the requirements of different well profiles.

Frank’s International’s Caseless Insertable float system (CIFS) is an “off the shelf” versatile float system that allows operators to standardize equipment, and reduce costs and lead time by eliminating the need to pre-order float equipment for planned contingency strings or to acquire float equipment for an unplanned casing stings. The CIFS also mitigates the financial risk of ordering back-up float equipment that cannot be used or has minimum usage on upcoming wells.

Frank’s International’s float system is a revolutionary adaptation of composite technology created to allow the operator to install a float valve and plug landing system directly into a casing, removing the requirement for customization to match casing grade and connections. All of this is accomplished while maintaining the ability to easily drill-out the casing shoe track. With its modular design, the system can be configured to various operational requirements, accommodating multiple configurations for plug landing surfaces, float valves and shoes. When provided as a float assembly, the system can be set up for conventional or auto-fill with ball-drop or ball-contained options along with varying flow conversion parameters.

Float system allows operators to install a float valve or guide shoe directly into a casing. The off-the-shelf solution reduces lead times. Courtesy: Frank’s International

Float system allows operators to install a float valve or guide shoe directly into a casing. The off-the-shelf solution reduces lead times. Courtesy: Frank’s International

The CIFS is simple to install in the customer’s existing casing string at either the pipe yard or rig site. Since it is installed directly into the casing, there is no need to source a bucking crew to make up the float equipment. The installation takes less than 30 minutes. Once installed, the anchor can be vacuum tested to verify sealing and anchor integrity, ensuring the qualification ratings can be achieved. Cement is susceptible to shrinking as it cures, which can lead to micro annuluses that can go undetected, causing seepage through the cement downhole. The CIFS uses an elastomeric seal versus traditional float equipment that relies on cement, that cannot be vacuum tested, to create the seal between the valve and body.

Tested and qualified to the API 10F standard, the CIFS system was run for the first time in deepwater with a 9-7/8” liner in the GOM on behalf of an independent operator on February 9, 2019. Running three float systems for true float valve redundancy, the assemblies were configured with the auto-fill float module.

The top assembly had a ball contained float and was set to convert at 2-4 BPM. At 3 BPM the circulation pressure dropped from 1,398 psi to 240 psi indicating the proper float conversion. After conversion, the ball was expelled to the subsequent lower floats for conversion. The large ID of the float system (>12.8in2 Flow Area) allowed the operator to run a 9-7/8” liner to TD while minimizing the surge on the formation.  After successfully converting the auto-fill float equipment, the primary cement job was performed, and the plugs were bumped on the top CIFS assembly to 1,500 psi. The floats were then checked, and the job was completed successfully. Once through the SSR plugs, the drill-out of the float assemblies took less than 30-minutes, each with a PDC bit. This performance was consistent with the quick drill-out times that operators have come to expect from typical composite constructed float equipment, with the added benefit of flexible configuration and reduced inventory requirements.

Following the success of the first run, the same operator was looking for a short lead time solution to minimize their customer owned inventory while maintaining a primary and backup option for float equipment on a 7-3/4” liner. The float System was determined to be the right solution for the operation. For this job, it was again decided to run three float systems in the auto-fill float module. The top assembly had a ball contained float and was set to convert at 2-4 BPM. At 3 BPM the float equipment converted, and the ball was expelled to the subsequent float assemblies.  The cement job was completed successfully, and the floats held after the job.

In addition to minimizing the quantity of customized casing accessories that the operator must store and maintain, the float System gives operators flexibility in their operations to acquire float equipment without manufacturing lead times. This is advantageous when looking at unplanned casing strings for sidetrack operations or low likelihood contingency strings. When these unplanned operations arise, they often leave the operator scrambling to find equipment to match their casing specifications. This accrues additional costs for expediting fees or having to machine crossovers to adapt available equipment with their casing string. Additionally, traditional float equipment operators must order equipment for wells three to four months in advance. Should market conditions change and a well is cancelled, they are left with equipment that might not be used elsewhere. The CIFS option takes this risk away from the operator.

With the oil and gas industry focused on optimization, efficiencies, and cost reduction, the CIFS offers a step change improvement by replacing traditional float equipment. It is positioned to establish a new standard when it comes to casing accessories, supporting operators in their drive to streamline operations and reduce unnecessary costs.


Amy Farrar
Author Bio: Amy Farrar is applications engineering manager, Frank’s International.