冲压模毕业设计题目:谁来帮我改改英文错误

Abstract
Weakly consolidated sand formation "spread" all over the oil zones in the world, so as the condition in our country. Generally, this kind of formation belongs to heavy oil reservoir with the characteristics of low depth of burial and the cementation of the rock by itself being weak. Sand production problem is serious in this kind of formation.
After investigating the basic characteristics of the weakly consolidated sand formation, the sand production problem with perforation process in this kind formation was analyzed and studied on the basis of the basic theories of rock mechanics in this thesis. The theoretical model was "built" for sand production problem in well completion in this formation by perforation. The factors that affect the sand production were analyzed and the following results were drawn. The more the heterogeneity of the "reservoir is and" the larger the maximum circumferential stress on the wall of perforation hole is, the more serious the sand production in oil well is and the larger the area of sand production is. No matter what condition is, for a perforation well, the perforation hole directing the orientation of the minimum horizontal principal stress is the mostly unstable one. So, when optimizing the perforation in weakly consolidated formation, sufficient consideration should be given to the characteristic of stress distribution caused by the heterogeneity of horizontal stress in situ, to design the perforation orientation reasonably.
前 言
出砂是弱胶结砂岩油藏开采中经常遇到的难题之一。在国内外各油田生产中，都广泛地存在着出砂问题，出砂原因极其复杂，钻井、完井、生产和修井作业等各个环节都可能引起地层出砂。油层出砂后，一方面砂子可能在井内沉积形成砂堵，使油井产量降低；另一方面将增加清砂的井下作业工作量、磨损设备和砂卡井下工具，如抽油泵的进出口凡尔、活塞、衬套等。出砂严重的井还可能引起井壁坍塌而损坏套管和衬管、砂埋油层导致油井停产，使采油的难度和采油的成本都显著提高。因此，研究油井的出砂机理、开展出砂趋势分析，有助于优化完井设计，制定合理的生产和开发方案，确保油井正常生产。弱胶结砂岩油藏分布广、储量大、产量占有重要地位，因此，研究油井出砂机理对石油工业具有重要意义。
本文在了解弱胶结地层基本特征的基础上，建立理论模型，分析了地应力和油藏压力状态对弱胶结砂岩油藏出砂的影响，预测了油井的出砂趋势，为进一步的防砂工作提供了指导。

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