Heat Oil Wax Technology Research And Application

In our country, most of the oil fields have the problems of paraffin deposit in the oil well. Thermal paraffin removal, having the characteristics of simple operation and quick response, has been widely used in the oil fields. Since the inaccuracy of judging the paraffin deposit degree in the oil well will lead that the thermal wash cycle and the parameter of thermal flushing is unreasonable, it causes the paraffin removal in the oil well has a poor effect, thermal efficiency is low and the oil layer get polluted. For this purpose, focusing on the diagnosis of the degree of the paraffin deposit in oil well and thermal wax removal technology, this paper forms a set of comprehensive technology skills for thermal paraffin removal in the oil well, writes the project of the thermal paraffin removal in the LX oil field and then succeeds to apply it to production practice in oil field. When the work above is completed, some achievements can be gotten as following:(1) With the hierarchical clustering method, before and after lifting the polished rod the load change of54paraffin troubled wells are divided into five categories, and corresponding to these categories, the degrees of paraffin precipitation are divided into free, slight, the serious, the more serious, very serious paraffin deposit. The change scope of polished rod load, determined by the degree of paraffin deposit is calculated, and the degree of paraffin deposit in oil wells of the same block can be diagnosed.(2) Taken the example of33oil wells with the same pumping unit and motor in LX oil field, the degree of paraffin deposit is determined by the upward current method. The ratio range of the measured and theoretical upward current is obtained by the empirical cumulative distribution function of MATLAB software. According to the method, the degree of oil well paraffin deposit can be quickly determined.(3) According to thermal deparaffin classification, this paper count and evaluate the variety of casing pressure, liquid production, oil production, upflowing current, maximum loading and minimum loading of44wells in LX oil field from2008to2012. Finally optimise the reasonable thermal deparaffin technique in every single well.(4) This thesis carry out the five curve method which plot the liquid production, oil production, up flowing current, maximum loading and minimal loading with time as the ultimate way to certain the wax removal period. And in this way. the thesis recount out the wax removal period for44wells in LX oil field.(5) The optimization of the thermal wash in the44wells of LX oil field oil shows:when the water cut (<15%) in the oil well is lower than average, dead crude can be worked as thermal washing medium; when the liquid producing capacity (>5t/d) is higher, production liquid can be worked as thermal washing medium; when the liquid producing capacity (<1.5t/d) is lower, the bottom water in the oil storage tank after crude oil dehydration can be worked as thermal washing medium, or stream can wash the well.(6) The formula for calculation of wellbore temperature distribution in the well is established. Applying this formula, the calculation of the Well LI-6-3is in accordance with the measured value. At the same time, analyzing the measured curves of heat wash in the oil well, the results show the inlet temperature should be increased to85℃form the low temperature of50℃, and the outlet temperature should be above10℃higher than the melting point of paraffin.(7) Thermal paraffin removal judgment program is written by the VB6.0software, which can judge the degree of oil well paraffin and the circle of heat deparaffin and simulate the distribution of temperature in the wellbore. So, the jobs of oil well paraffin removal can be more effectively regulated and guided.