Cementing technologies to adjust drilling fluid properties before cementing and displace mud by turbulent prepad fluid at low return-velocity.;

This paper, first of all, analyzes some technical difficulties in horizontal well cementing such as safe casing running, displacing, free water, mud mixed oil, casing centering, hole condition, and so on, then studies some techniques such as cement slurry and pad fluid system, safe casing running, casing centering, and so on.

Autogenetic heat fracturing technique, which replaces fracturing pad fluid with chemicals in order to increase the backflow volume of fracturing fluid and the oil well productivity, is a technique used for remaking the low permeability reservoirs.

Taking an oil soluble resin A with good stability as the main material, a temporary-bridge ahead fluid used in high permeability cement sand control technology was developed in the paper.

For fracturing design,ahead fluid volume is an important operation parameter,which directly influences fracture morphology,fracture results or even results the success or failure of the operation.

8 mm casing,the cementing program and procedures are deeply studied,it is determined to use the preflush system developed by Southwest Petroleum University which is highly effective in preve.

It is particularly important to choose right ingredients of the spacer for well cementing in sea-water drilling fluid.

The capacity of the prepad fluid( spacer fluid, washing fluid) of slurry is directly related to whether the cement job will succeed or not.

In consideration of the characteristics of high bottomhole temperature, high formation pressure and oil base fluid used for deep well drilling in Yingqiong Basin in South China Sea, a high density prepad fluid system with flush and separation functions is developed.