TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper presents laboratory and field data for using a settable spotting fluid (SSF) to help improve the subterranean zonal isolation of primary cement jobs on expandable liner installations. A SSF can add value to the well construction process when well conditions for cementing are less than optimal; i.e., low annular velocity, no pipe movement, poor casing centralization, or poor mud conditions. Many of these unfavorable conditions are present when expandable casing is installed.Past SSF designs used blast-furnace slag and were limited to temperatures less than 90°F (32°C). The new SSF incorporates a hydraulic material with a non-blast furnace slag and is formulated for water-or oil-based wellbore fluids. Although the new SSF is optimal for displacement in the cementing process, the SSF will set to a state for providing zonal isolation if it is bypassed during the cement displacement process. Depending on the time required to run and expand the casing, the SSF can be formulated to remain liquid for a few hours or as long as three weeks. However, the high pH condition and heat of hydration from the placed cement in the annulus can accelerate the set of the SSF to a few hours.The achievement of a near-100% annular seal occurs even when poor cementing conditions are present and without the use of rheologically tuned spacers. Job data from field trials also show improved shoe integrity and higher pipe-to-cement bond, echoing the results from the laboratory tests.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper presents laboratory and field data for using a settable spotting fluid (SSF) to help improve the subterranean zonal isolation of primary cement jobs on expandable liner installations. A SSF can add value to the well construction process when well conditions for cementing are less than optimal; i.e., low annular velocity, no pipe movement, poor casing centralization, or poor mud conditions. Many of these unfavorable conditions are present when expandable casing is installed.Past SSF designs used blast-furnace slag and were limited to temperatures less than 90°F (32°C). The new SSF incorporates a hydraulic material with a non-blast furnace slag and is formulated for water-or oil-based wellbore fluids. Although the new SSF is optimal for displacement in the cementing process, the SSF will set to a state for providing zonal isolation if it is bypassed during the cement displacement process. Depending on the time required to run and expand the casing, the SSF can be formulated to remain liquid for a few hours or as long as three weeks. However, the high pH condition and heat of hydration from the placed cement in the annulus can accelerate the set of the SSF to a few hours.The achievement of a near-100% annular seal occurs even when poor cementing conditions are present and without the use of rheologically tuned spacers. Job data from field trials also show improved shoe integrity and higher pipe-to-cement bond, echoing the results from the laboratory tests.