DOC-LET is the system of reducing the cement slurry density and is main composed of solid weight lightness materials such as natural glass beads, artificial glass beads and so on. Low density system usually contains enhanced materials which are used for improving the strength and other additives which are used for improving the performance of cement slurry. Based on the linear packing model, solid suspension model and particle dense packing theory, the system can increase the solid content of cement slurry per unit volume and enhance the compactness of cement paste. Reasonable materials are used to improve the surface properties of materials so as to reduce the filling water between materials and lubricating water of materials surfaces, bring good rheological properties and improve the whole performance of cement slurry.
DOC-LET can be divided into four series according to the temperature and the well condition.
Series Constitution
DOC-LET system includes:
DOC-LET GR General low density and high strength system: suitable for general cementing, medium and low temperature cementing.
DOC-LET LT Low temperature and low density system: suitable for deep water low temperature surface cementing.
DOC-LET HT High temperature and high density system: suitable for high temperature wells cementing.
DOC-LET UL Ultra low density system: suitable for cementing under ultra pressure condition.
System Composition
1、Oil well cement: class G.
2、Weight lighting agent: DOC-P61/P62.
3、Enhancer: DOC-BT1 DOC-BT4.
4、Fluid loss additive: DOC-G71S DOC-G80L.
5、Accelerator: DOC-A90S.
6、Dispersant: DOC-F44L DOC-F45L.
7、Anti-channeling enhancer: DOC-GS12L DOC-GS12S.
8、Retarder: DOC-H21L.
9、Expander: DOC-B10.
10、Defoamer: DOC-X60L.
System Features
1、Optimizing cement system using particle size grading technology .
2、Select different types of natural and artificial glass beads.
3、Good settlement stability of cement slurry.
4、Compactness and low permeability of cement paste.
5、Improve the performance of cement slurry using different functional materials .
