Reserch on anti-cracking function of big-size gravel;

Looks into in the way of the performance on the gravel flexible primary level asphalt pavement route;

Based on the water quality and climate of the oil contaminated lake in Daqing area,four simulated subsurface wetland systems were constructed in the field to study their removal effect of oil in lake water,including the gravel bed,the gravel-reed bed,the slag-reed bed and the slag bed.

Analysis and correction of DePriester gravel size model and its applications;

According to the basic mechanism of tip screen out(TSO) frac-pack sand control and considering the effect of well stimulation and sand control,the design optimization method for gravel size was developed.

Therefore,gravel size design is the key step of gravel-packing sand control optimization.

A method of calculating productivity for gravel packed well;

There exist many factors influencing the productivity in gravel packed and sand controlled wells, its correlation is complex, a precision and practical model for prediction is hard to be established by using conventional theory.

Based on what had been done previously in the aspect of pressure losses across perforation and gravel pack, the paper presents a new formula to calculate the pressure losses across perforation and gravel pack,and calculates the skin factor through the introduced popular equation of radial flow.

Research on PDC bit for drilling in gravel interlayer.;

That is deviding vally into four big and eight small area according to Aibi Lake ecology chain effection and each area character in different area,raises the relative prohibition herding,grave covering,windbreak forest and etc,protection and recoverying measures.