不同井深用膨胀筛管基管材料的研究

【作者】 季正勇；

【导师】 李春福；

【作者基本信息】 西南石油大学 ， 油气田材料与应用， 2011， 硕士

【摘要】 本文介绍了膨胀筛管的组成、膨胀工艺、膨胀工具及材料的选择等问题,并针对不同井深选择了三种材料作为膨胀筛管基管进行实验,实验包括金相分析、力学性能分析、断口形貌分析、腐蚀电化学分析及有限元分析。实验研究表明在室温条件下,15CrMo钢、316L不锈钢和21Cr5Mn24Al2Si钢的塑性都能满足制备膨胀筛管基管的最基本要求,但在不同的井下温度场条件下表现出不同的结果。即,三种膨胀筛管基管材料的力学性能都不同程度地受到井下温度场的影响。15CrMo钢的抗拉强度(Rm)、屈服强度(Reh)和延伸率(A)受井下温度场的影响情况不同,随着温度的升高,抗拉强度(Rm)和屈服强度(Reh)都略有升高,而延伸率(A)且以较大的幅度下降；316L不锈钢和21Cr5Mn24Al2Si钢的抗拉强度(Rm)、屈服强度(Reh)和延伸率(A)受井下温度场的影响较大,随着温度的升高,抗拉强度(Rm)、屈服强度(Reh)和延伸率(A)的下降幅度都较大。三种材料中,316L不锈钢最耐腐蚀,21Cr5Mn24Al2Si钢次之,15CrMo钢的耐腐蚀性最差。有限元分析计算结果中,15CrMo钢、316L不锈钢和21Cr5Mn24Al2Si钢在不同膨胀率下膨胀后的等效应力分布相类似,最大值相差不大,其主要分布在割缝尖端的附近；温度和膨胀率对15CrMo钢膨胀时和膨胀后的性能影响较小,膨胀率对316L不锈钢和21Cr5Mn24Al2Si钢膨胀时和膨胀后的性能影响较小,而温度对其影响较大；有限元分析的计算结果是实验室实验结果的90%,所以有限元分析的计算结果是可靠的,能对现场施工起到指导意义。最后,通过实验和有限元分析得出,15CrMo钢、316L不锈钢和21Cr5Mn24Al2Si钢都可以制备膨胀筛管基管,但其应用的井深和井况不同。15CrMo钢是一种耐热的珠光体钢,其能耐550℃以下的高温,但耐腐蚀性较差,只能适用于腐蚀较轻的油气井；316L不锈钢是一种奥氏体不锈钢,其耐腐蚀性能较好,但强度受温度的影响较大,其主要用于常规井况的井中,一般井深在1000-2000米；21Cr5Mn24Al2Si钢的综合机械性能较好,不但强度和延伸率较高,而且还具有较好的耐腐蚀性能,故其制备的膨胀筛管基管能用于腐蚀性较强和深井及超深井。更多还原

【Abstract】 The article introduces the constitution of expansion screen pipe, expand craft, and selection of materials. Followed by it, the author selects three materials as inflation sieve tube base tubes to do the experiment. It includes metallographic analysis, mechanical property analysis, Fracture morphology analysis and fem analysis.According to experimental study, at room temperature conditions the ductility of 15CrMo steel、316L stainless steel and 21Cr5Mn24A12Si steel, all meet demand for preparation of inflation sieve tube base tube, but in different well temperature conditions show different results. The mechanical property of three inflation sieve tube base tubes was influenced by well temperature in different extent. The Rm、Reh and A of 15CrMo steel has different influence by temperature, as the temperature increases, the Rm and Reh have a tiny increases, and the A has a larger amplitude drop; the Rm、Reh and A of 316L stainless steel and 21Cr5Mn24Al2Si steel are severely influenced, as the temperature increases, the Rm、Reh and A have a larger amplitude drop. In finite element analysis, equivalent stress distribution of 15CrMo steel and 21Cr5Mn24A12Si steel, and 316L stainless steel are the same after different expansibility, the maximums of them are totally the same and are distributed around kerf spiry; for the 15CrMo steel, temperature and expansibility have a tiny influence on performance, while, for 21Cr5Mn24A12Si steel and 316L stainless steel, expansibility also has a tiny influence on performance, temperature is on the opposite side; calculated results of fem analysis is 90.08% of the results in laboratory, therefore, it’s reliable and can be used in site operation.Finally, according to experiment and fem analysis,15CrMo steel、316L stainless steel and 21Cr5Mn24A12Si steel can preparation expansion screen base pipe, but their application different well depth and well conditions.15CrMo steel is a kind of heat-resistant pearlite steel, it can resist 550℃, but it cannot resist corrosion, so can only applicable to lighter corrosion wells.316L stainless steel is a kind of austenitic stainless steel, the corrosion resistance performance is better, but by the influence of the temperature of the intensity bigger, so can applicable to the not complex wells and the well depth in 1,000 to 2,000 meters. 21Cr5Mn24A12Si steel has good mechanical performance, not only strength and elongation is higher, but also has good corrosion resistance, so it can be used to the complex well、deep well and ultra deep well.更多还原