|Publisher||Offshore Technology Conference||Language||English|
|Content Type||Conference Paper|
|Title||AN ASSESSMENT OF GROUTING MATERIALS, PLACEMENT METHODS, AND MONITORING EQUIPMENT FOR OFFSHORE STRUCTURES|
|Authors||C. Callis, C. Knox, D. Sutton, and S. Wiley, Halliburton Services|
Offshore Technology Conference, 30 April-7 May 1979, Houston, Texas
|Copyright||1979. Offshore Technology Conference|
Grout placement techniques, technology of grouting materials, and methods for monitoring grout quality and grout placement are presented.
Placement methods using new generation high pressure packers and inflation-grout manifolds are discussed. High pressure packers have made single stage grouting jobs a practical reality. Reliable inflation-grout manifolds have eliminated many lines previously needed for packer inflation and placement of grouting materials.
In addition to traditional grouting materials, new materials to promote high bond strength, control self-desiccation, and minimize shrinkage are discussed. Grouts are classified according to use and typical examples are given. Methods and equipment for controlling grout density and grout placement are included.
Platform grouting is the process of placing a cementitious material into the annulus between a jacket leg and pile. This operation has advanced to the point now that an operator has a variety of methods, materials, and tools from which to choose. For example, at least five different methods for grouting platform legs are commonly used with variations existing within each method. Terms for each of these methods, although not standard, might be (1) conventional two stage, (2) packer, (3) balanced pressure, (4) two stage delayed set for insert piles, and (5) two stage inner string for insert piles.
Recent advances in methods, materials, and tools have helped make platform grouting more trouble-free and dependable. This paper will review these advances and provide an overview of current platform grouting in general.
Conventional Two Stage
As shown in Fig. 1, this method usually involves a mud wiper seal at the bottom of the annulus. This serves to help reduce mud contamination of the annulus as the pile is driven through the jacket leg and it also helps support the first stage of the grout. This technique normally involves running two separate grout lines from the surface. The first stage line enters the annulus just above the mud wiper seal. Second stage line enters the annulus 5 to 30 ft above the first stage grout line depending on the length of plug required. First stage grout is normally a quickset type and fills up to the second stage grout line entry level. While the first stage is setting, water should be circulated through the second stage grout line to displace any grout that may have covered the second stage port. Once the first stage grout is set, the second stage is injected to the desired height in the annulus.
An improvement to this procedure, shown in Fig. 2, makes it possible to accomplish the grouting through only one grout line from the surface. One line is run from the surface to the lower grout inlet. A pipe is run from the upper grout inlet to a sleeve-type flow control valve installed in the grout line at the same elevation as the upper grout port.
|File Size||862 KB||10|