With the introduction of self-made reinforcing material KZ and early-strength toughening agent ZR,combining with the optimization of chemically modified fiber at the lengths of 600 μm and 1 050 μm as the toughness reinforcing material,four kinds of different new quaternary lightweight cement system were finally developed with the density ranging from 1.

Analyses were done on the factors affecting the quality of the adjustment wells,such as hole enlargement,mud properties,density of cement slurry,pore pressures of the formations and the flow velocity of the .

Study and application of an early strength stabilizing agent for light weight cement;

According to the characteristics of micro-fine cement, a compound early strength agent and light weight cement with 1.

The geologic background of low density cementing used in Tahe Oilfield is introduced.

Based on the analysis of particle size distribution and the optimization of low density cement system formulation using laser grain size test and related compatibility experiment.

The low-density cement slurry is usually required in the common cementing operation in low-pressure leakage well.

Low-density cement slurry application in the field becomes more extensive, Mainly in order to prevent the loss of easy leakage layer with low pressure and to meet the demand for one-time long closure, at present, the oil field study of low-density cement growing, However, the density of the slurry within the scope of 1.

2～3%DWZ-A-7+4%DWZ-B+4%DWZ-C(0～20℃)2～3%DWZ-A-7+4%DWZ-B+3%～4%DWZ-C(20～30℃)The optimal formulas of DWZ-Ⅱseries are as follows:2～3%DWZ-A-7+4%DWZ-B+4%DWZ-C+5%micro-silica(0～20℃)2～3%DWZ-A-7+4%DWZ-B+3%～4%DWZ-C+5%micro-silica(20～30℃)The results show that the additives of DWZ-I series are compatible with the low-density cement slurry with density larger than 1.