Oil Well Pipe Material Liquid-solid Two-phase Flow Erosion-corrosion Studies

The materials of P110and super-13Cr are commonly used in the oil and gas developmentfor their excellent properties both mechanics and economy. The solid-liquid two-phase lfuid,which usually contains corrosive medium (CI~-)was formed in the process of fracturing. Thestirngs and casings are damaged by the erosion-corrosion synergy of fracturing fluid earringthe proppant under large displacement and high proppant concentration. It is significant forfracturing engineering and new materials development to studying for the behaviors oferosion-corrosion for P110and super-13Cr.In this paper, the behaviors of erosion-corrosion for PI10and super-13Cr were studied bythe jet expeirment equipment. Two kinds of mediums including the distilled water and3.5wt%NaCl solution with different concentration quartz sand were used in the experiments. Theerosion time,velocity,angle of the erosion and sand content were investigated comprehensively.Further more, the quantitative investigation for the interaction with above factors wereimplement combing the experiment results with electron microscope images.The results show that the erosion rate in the medium of3.5wt%NaCl is higher than theone in the distilled water. Two materials erosion rate increase with the flow rate. The criticalvelocity is about5.6m/s in the super-13Cr materials，but it has not appeared in the PI10material. The "blocking effect" appears in the two materials in the experiments, and theerosion rate with the sand content3when it is more than25kg/m~3, When the sand content is50kg/m~3, the interaction with solid particles reaches the maximum, which leads to erosionreaches rate the minimum. The Loss weight of the two materials are increased with the erosiontime, while the erosion rate decreases ifrstly and then increased slightly, when the erosion timeis in range from60min to90min，PI10material erosion rate tends to be stable, andsuper-13Cr material erosion rate tends to be stable when the erosion time is in range of90min to120min. PI10material has the maximum erosion rate when the erosion angle is45°,and the maximum erosion rate appear in super-13Cr material when the erosion angle is30°or90。. In the mixed solution of3.5wt%NaCl and quartz sand, mixed solution, The interactionof erosion and corrosion will be appear in two materials. The effect of interaction in super-13Cr mateirals is more serious than that in PI10mateiral. The severity of injuires to the twomateiral’s erosion interaction successively are the velocity, sand content, erosion time, erosionangle. In the various effect factors，the erosion angle affect would raise "Negative InteractionErosion" in super-13Cr material.The erosion-corrosion mechanism of P110material is mainly cutting. The materialerosion is severe erosion when the erosion angle is small. For the super-13Cr materials, whenthe erosion angle is smaller, the erosion-corrosion mechanism is mainly is cutting. With theangle increases，the impact of the positive is gradually increasing. The secondary erosion wearor deformation may occur when the erosion angle is90°.