油井出砂机理研究及其在吐玉克油田的应用

【作者】 雷征东；

【导师】 刘向君；

【作者基本信息】 西南石油学院 ， 油气田开发， 2003， 硕士

【摘要】 本文以岩石力学基本理论为基础，定量和半定量地研究了油井出砂的影响因素。建立了判别射孔完井地层出砂趋势的线弹性的解析模型，该模型来半定量的分析生产压差、压力衰歇、温度升高对油井出砂的影响；建立考虑粘度影响后的基本微分方程，通过有限差分分解来分析稠油粘度对油井出砂的影响。 通过研究表明：地层非均匀性越大，射孔壁上最大周向应力越大，油井出砂越严重，而且出砂区域也越多；强化开采不利于射孔孔眼稳定，在地层较弱时，不恰当的压差将可能引起地层过早、过量出砂；随着油藏压力衰减，射孔孔眼发生剪切屈服，出砂的可能性随之增大；温度升高会产生了热应力，使围岩的切向应力增大，当由于温度变化产生的膨胀应力和原地应力引起的井壁围岩重新分布的应力超过岩石强度时，就易发生剪切破坏；稠油粘度越大，拖曳力越大，而且会引起井壁应力的增加和油井周围压力下降，从而导致油井出砂；油井注水会产生粘土膨胀、微粒运移，还会导致岩石强度降低、井壁上岩石应力减小，从而导致油井出砂。 把上述的研究结果结合TH油藏的测井资料和出砂现状进行分析，得出TH油藏的出砂主要因素。在分析了出砂机理以后，结合TH油藏出砂严重的现状和油藏特征，选择适合油藏特定条件的合理防砂方法。本文采用多级综合模糊评判方法对各种防砂方法主要进行技术评价，该方法克服了以往防砂优选中难以兼顾各种因素、适应界限难以界定的问题，评价结果更加客观公正。总之，对出砂油井，应从钻井、完井、生产全过程系统地考虑防砂，制定相应的防砂措施。更多还原

【Abstract】 This paper research on the sand production mechanism quantitatively and semiquantitatively,which are based on theoretics of rock mechanics.The linear-elastic model was established for peforation’s formation,by which the sand production trend can be judged and analyzed, this paper studys drawdown pressure and the depletion of formation pressure and temperature increment and affusion to sand production. Establishing elementary differential eguation with considering viscosity infection,through the medium with finite difference decompounding to analyse the effect of high-viscosity oil’s viscosity to sand production in oil well.The results indicate that the heterogeneity of reservior is larger, upper maximaxcircumferential stress of perforation’s wall is larger, sand production in oil well isseverity, forced production have maleficence on stabilize of peforation’s reservoir ,in weakly consolidated sand formation, impertinence production pressure will induce the early and excessive sand production. With the depletion of reservoir pressure,some area around borehole will suffer,the possibility of sand production will become big.Increment of temperature would produce heat stress, which enlarges wall rock’s tangential stress, when rock redistribute’ stress exceeds the intension of rock strengthowing to temperature fluctuation as far as easily occur shear failure, consequently resultinduces sand production.The larger high-viscosity oil viscosity is,the larger haulier is,in additional would increase the tangential stress and descend pressure circumference ofoli well, Sequentially induce sand production of oil well.Major factors of sand Production are educed from combining result of studying with Logging information and present status of sand production in TH oil reservoir.after the analyses of sand Production mechanism, combining sand Production severely present status TH oil reservoir’s with characteristic of reservoir, select a fit way to oil reservoir condition.select a way of sand control in reason to fit for special condition, This article adopts the way of multistage synthesize blur judge to principallyevaluate kinds of way of sand prevention technology, it overcomes that ancientlyoptimization way of sand control was hard of thinking about different kinds of factor,and is hard of confirming the margin, the result with evaluation become objective and fair.In a word,we should systematically consider sand control during drilling well, well completion and all the processes,and make measures of sand control.更多还原