Abstract: Widely distributed unconsolidated formations become a special challenge to the completion specialists as production rate and life of the well depend on successfully controlling or eliminating sand production.Warm-air coking for sand control is a new technique which makes the crude oil react with the injected warm-air and split to coke to consolidate the formation.In this paper a testing device is designed and made for laboratory study on warm-air coking for sand control.The results of the experiment show that the highest temperature of the hot-air,the time of treatment and the flow rate of air are the major parameters to affect the coking result.The composition analyses of the treated cores indicate that (1) Under high temperature,various complicated chemical reactions occur,most of which are oxidation reactions;(2) The reactions turn some of the maltene and resin into asphaltene,and under high condensation the asphaltene changes into high-molecular toluene-undissolved materials;(3)A certain amount of resin and toluene-undissolved materials in the core is essential to obtain high compression strength;(4)Permeability of the cores treated by warm-air coking reduces about 20%;(5)The heavy oil must contain a certain amount of original asphaltene to form a core with high comperssion strength.

Key words: warm-air-coking, sand control, laboratory experiment, composition, analysis, coking mechanism

摘要： 油井防砂工艺技术的研究与发展对疏松砂岩油藏的正常开采至关重要.焦化防砂是通过向地层内注入热空气使原油在高温下发生氧化裂解生成焦炭从而将地层砂固结的一种防砂新技术.为了对该项技术进行全面系统的理论分析与评价,设计并制作了一套焦化防砂实验装置,利用该装置进行了焦化防砂室内实验研究.焦化效果以岩样的抗压强度进行评价,实验结果表明,影响焦化后岩样抗压强度的主要因素为空气最高温度、处理时间和空气流量.此外,对焦化处理后的岩样所作的岩样组成分析揭示出,稠油胶结机理为氧化作用使部分油分和胶质变成沥青质,沥青质受到高度的缩合作用而成为高分子量的甲苯不溶物.由于新生胶质的氧化比原生胶质的氧化困难得多,因此适合焦化防砂的油层,其原油必须含有一定量的原生胶质和沥青质.

关键词: 焦化, 防砂, 室内实验, 岩样, 分析, 胶结机理