The phenomenon of the oilwater two phase mixed flow is often encountered in the gathering and transportation pipeline, and the study of its pressure variation is important for the gathering pipeline design and operation. Using VOF model to simulate numerically the oilwater two phase flow in bend duct of oilfield surface gathering pipe under different moisture content of crude oil and fluid velocity. Through the analysis of the calculation results, it was known that the moisture content of two phase flow and flow velocity has great influence on the pressure drop in bend duct. With the increase of moisture content, the two phase flow pressure in bend duct increases.The elbow inner wall pressure is reduced while the speed increases, the outer wall of the pressure increases while the rate decreases. While increasing the flow rate, the high moisture content of the oilwater two phase pressure drop first decreases and then increases.

Exploitation and research of compositive product, i.e. Corrosion Inhibitor, was carried out by the mixing of the main component of corrosion inhibitor with surfactants, chelate, organic amine and liquid of prefabrication, then the optimal proportion was found out in order to build the best matching systems. The models among the anti-corrosive capacity of the inhibitor and operation conditions were established by polynary quadratic regression. The optimum operation conditions obtained by non-linear programming (NLP) are the following: the amount of the surfactants, chelate, organic amine and the liquid of prefabrication is 0.112 6, 0.010 2, 0.213 9 and 0.357 2 respectively. The verified experiment showed that the products under the optimum operation conditions had the better water-soluble capablity, slower corrosion rate and higher anti-corrosive capacity (up to over 99%).