| In this thesis, heavy oil of Lukeqin in tuha oilfield as raw material, aimed at the reservoir with low temperature (80?), the quantitative wells deep (2000-3000 m), and heavy oil of lukeqin have high density, high viscosity, high freezing point, non hydrocarbon content and middle high wax content characteristics of mining use very difficult problems, on the basis of research literature at home and abroad, and decided to adopt the air injection low-temperature catalytic oxidation enhanced heavy oil recovery technology, the technology has the advantage of high efficiency low cost and no damage to formation, but the implementation of the key problems are the low temperature catalytic oxidation reaction of heavy oil, quickly consume oxygen in the air, to ensure the safety in production. This article mainly divided into three parts: (1) preparation and evaluation of catalyst used in the air injection low-temperature oxidation production technology; (2) the air injection low-temperature of heavy oil catalytic oxidation indoor experimental research; (3) the air injection technology implementation process safety evaluation.Using the direct saponification method and metathesis reaction of the 12 kinds of oil-soluble organic acid salt catalyst, explore a kind of polymer viscosity of heavy oil oxidation catalyst, through comparing the catalyst oil soluble, heavy component percentage before and after oxidation of heavy oil, acid value, and the change of oxygen, carbon dioxide content in the exhaust, preliminary selected four kinds of suitable catalyst for heavy oil of Lukeqin air injection catalytic oxidation experiment.In reservoir temperature 80 ?, under the condition of air injection pressure 2 MPa, the static oxidation reaction of 10 d, selected the suitable Lukeqin heavy oil inject air of low temperature catalytic oxidation catalyst CuL, its dosage is 0.1% (quality of catalyst/oil ratio), at the same time, the influence of gas injection pressure and moisture content in heavy oil oxidation experiment was studied. In the optimal experimental conditions, the oxygen content in the tail gas of heavy oil by 21% to 4.25%, the oxidation of oleic acid value increased from 1.73 mgKOH/g to 5.19 mgKOH/g, CO2 content also increased from 0 to 2.78%. Compared with crude oil, oil oxidation SARA group composition of light component (saturation and aromatic) content increased from 61.03% to 61.03%, heavy component (resin and asphaltene) content from 38.97% to 33.85%, the product quality is improved obviously.Evaluated the air injection stage, soak oxidation stage and production stage of the process safety, analyzed the security of production well. When produced fluid moisture content of 30%, calculated on the safety of the shaft lifting process:(1) the concentration of nitrogen to slowly rise,600 m from the well's mouth began to gradually reduce, achieved the minimum at the well's mouth; (2) from the bottom to 400 m from the well's mouth, do not have conditions of explosion, from 400 m to the lower explosive limit rapidly decrease at the mouth of the well to achieve the minimum 6.83%; (3) methane content has always been to 0,600 m from the well's mouth began to free, methane at wellhead maximum 2.74%, still less than 6.83% methane explosion limit at this time, not an explosion; (4) near the real oxygen concentration was 4%, slightly declining, always less than the minimum critical oxygen content is 13.66%, so the air injection technique is safe.As the increase of moisture content extraction liquid, wellhead methane concentration decreases, when the moisture content of 70%, wellhead corresponding theoretical critical oxygen content as high as 33.41%, more than 21% oxygen in the air, which is need to under the condition of oxygen enriched blast, production process becomes more secure. Consider other aspects of the situation and field application, to ensure the safety of the oxygen content standard of 10.93%. |
PDF Full Text Request