Flow Characteristics of Crude Oil with High Water Fraction during Non-heating Gathering and Transportation

In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil with high water fraction was studied in a flow experimental system of the X Oilfield.Four distinct flow patterns were identified by the photographic and local sampling techniques.Especially,three new flow patterns were found to occur below the pour point of crude oil,including EW/O&W stratified flow with gel deposition,EW/O&W intermittent flow with gel deposition,and water single-phase flow with gel deposition.Moreover,two characteristic temperatures,at which the change rate of pressure drop had changed obviously,were found during the change of pressure drop.The characteristic temperature of the first congestion of gel deposition in the pipeline was determined to be the safe temperature for the non-heating gathering and transportation of high water cut crude oil,while the pressure drop reached the peak at this temperature.An empirical formula for the safe temperature was established for oil-water flow with high water fraction/low fluid production rate.The results can serve as a guide for the safe operation of the non-heating gathering and transportation of crude oil in high water fraction oilfields.

Production of 48MnV-C non-heat treatment crankshaft steel by means of converter plus continuous casting and hot-rolling process

48MnV-C non-heat treatment crankshaft steel is specially used for making crankshafts of Cummings C engines.It mainly adopts the technology of V—N micro-alloying,at present,it has been successfully used in making crankshaft of heavy duty truck engines.BX STEEL made trial production by means of converter→secondary metallurgy(RH + LF)→rectangular slab caster→hot rolling process,and studied the T[O],T[N],[H]and non-metal inclusion in 48MnV - C steel under continuous casting process condition,the actual grain size and the slab quality.All the chemical compositions and test results met the needs of Cummings Crankshaft Steel Standard.In order to ensure the mechanical properties of the non-heat treatment steel,a certain amount of nitrogen is added to it,also a small amount of sulfur is added to improve the cutting property of the steel.This process route can make full use of the de-hydrogen function of RH,and during RH treatment,rough adjustment of alloy elements may be made while the adjustment of Nitride Manganese nitrogen pick up and adjusting Mn,as well as Ca treatment and S content adjustment may be done during LF treatment so as to ensure the requirement of high nitrogen,low hydrogen,low oxygen content in 48MnV-C steel.Magnetic marks are defects shown in magnetic powder testing after the steel was used to make finished crankshafts.The 48MnV - C non-heat treatment crankshaft steel produced by means of the above-mentioned process route has not only relatively high robust performance which meets the needs of truck crankshaft safety,but also high qualification rate and basically no 'magnetic marks' are found after being made into finished crankshafts,which meets the crankshaft standard.Therefore,this steel has been widely used in domestic crankshaft industry.

Influence of Oil and Water Components on Wall-sticking Occurrence Temperature in High Water-cut Crude Oil Pipeline

To study the wall-sticking phenomenon and prevent pipeline blockage accidents,two analytical methods are used to evaluate the influence of different crude oil components on the wall-sticking occurrence temperature(WSOT).The WSOT and the interactions among oil,water,and surface solids are measured and calculated by various devices under different values of the wax content,water pH,and salinity.The results show that there is greater correlation between the wax content and WSOT than between resins/asphaltenes and WSOT.Furthermore,the wax content,water pH,and salinity have different effects on WSOT.There is generally a positive correlation between wax content and WSOT,whereas the maximum WSOT occurs when the water pH is in the range 5.7–6.5,and decreases under more acidic or alkaline conditions.As the salinity increases,WSOT decreases slightly,but quickly becomes saturated.In terms of interactions,variations in the interfacial tension and adhesion work with pH and salinity are consistent with that of WSOT,while the contact angle exhibits the opposite relation.