The effects of HCO3- concentration on CO2 corrosion for Q235 steel were investigated by weight loss tests and potentiodynamic polarization curve and EIS (Electrochemical Impedance Spectroscopy) techniques. The results showed that the corrosion rate of Q235 steel decreased wih on increase of HCO3- concentration when [HCO3-] was lower than 600mg/L. An evident active-passive behavior exhibited in anodic process at 1000mg/L·HCO3- .The cathodic reactions were promoted by increasing [HCO3-] when it reached 1000mg/L, H2CO3 and HCO3- become the most important cathodic reaction. Anodic behavior was an active process at higher [HCO3-] concentration and the anodic current density increased with the increase of [HCO3-] concentration.

In this corrosion test, simulated brine is used as corrosion medium, added different concentrations of aloe juice. Static weight-loss method is employed, meanwhile, we calculated corrosion rate of Q235 steel and researched on the corrosion inhibition effect of aloe in different temperatures. Results show that aloe is a good inhibitor, rate of corrosion inhibition can reach 80% or more and suitable for the temperature of work environment is less than 60 °C.

Add different concentrations of honey into the simulated brine, then study the corrosion of Q235 steel and the corrosion inhibition effect of honey in different concentrations and temperatures with the method of losing weight. Results show that honey is a good inhibitor.

This article describes the principles and methods of evaluating DRA in the lab, then evaluate the effect of DRA in the lab by designing a DRA test loop. This is measure that thoes DRA difference concentration be provided with flow increase rate and Drag reduction rate in test loop.

In view of rapid water cut increasing and poor oil recovery with banded distribution with high permeability belt in sandstone reservoir of Huabei Oilfield,the electrical bridge technique for water shut-off is proposed. Based on years practice of vertical wells and similarity in Ohms and Darcys laws,the electrical model involved variable resistors series/parallel instead of reservoir distribution,the arm-bridge circuit combined with signal detection. Then response of the circuit by variable water shut-off could be simulated. The results indicated that,the driving pressure and seepage quantity at mid-low permeability channel could be greatly improved by the strong in-depth water-plugging at high permeability channel (L=20~40m),and the low permeability flowrate increased to a maximum of 55.3%. Then the gel dam in-depth fluid diversion technique was verified by water plugging and circuit simulation. The conclusions provided a valuable guidance for horizontal wells development enhanced.