砂岩储层的伤害诊断技术与伤害解除对策研究

【作者】 王亚娟；

【导师】 赵立强；

【作者基本信息】 西南石油学院 ， 油气田开发工程， 2005， 硕士

【摘要】 砂岩储层酸化是目前最常用的油水井投产前及生产中的增产增注措施之一。在酸化解除钻、完井、注水及生产作业对储层造成的伤害之前,需要对储层伤害程度进行评价,传统的方法是通过试井分析求得的储层伤害表皮系数来评价储层伤害状况。 本文的分析表明,在以解除伤害为目的的砂岩储层酸化设计中,利用试井分析方法评价储层伤害有一定的局限性,且现场实践中很多需进行酸化解堵的井实际上很难取得试井分析资料。试井分析的局限性导致了它只能给出一个比较笼统的储层伤害表皮系数,而对于储层伤害的详细信息如主要伤害及其伤害范围无从得知,而这些信息对于砂岩储层酸化解堵中酸液配方、酸液用量、酸液浓度以及酸化规模等的设计是至关重要的。为此,本文提出了储层伤害定量诊断方法,该方法可确定造成储层伤害的主要和次要因素及伤害程度,弥补了传统的试井分析方法的不足,为砂岩储层酸化设计的优化提供了有力保证。 储层伤害定量诊断方法的核心是确定储层分项伤害因素的伤害程度和伤害范围。本文基于对储层伤害的内、外因的研究分析,对油水井中的钻井液固相及滤液堵塞、微粒运移、水化膨胀、无机垢堵塞和有机垢堵塞以及注水井中的水质污染、细菌堵塞等常见的储层伤害因素进行了数学模拟研究,建立了诊断各种伤害的数学模型,并利用所建模型进行了实例计算和分析。 同时,本文对水平井伤害也做了有益的研究,两种水平井表皮系数模型的对比表明Furui-Zhu-Hill的模型更为合理,并利用该模型对水平井伤害表皮系数进行了影响因素分析。 在搞清伤害主次的情况下,为了达到对症处理储层伤害的目的,本文针对特定的伤害进行了专用伤害解除技术研究,实现了油水井解堵增产技术配套,并结合伤害诊断结果,建立酸化解堵优化目标,进行了砂岩储层酸化解堵优化设计。 要使储层解堵取得较好的增产增注效果,不仅要有针对性很强的高效处理工艺,而且要把储层伤害降低到最低程度。 根据所涉及的模型和相关算法,编制了储层伤害识别诊断及酸化解堵设计程序,形成了一套较为系统的从储层伤害诊断到伤害解除对策的方法和流程,并给出了计算与分析,得出了一些有指导意义的结论和建议。更多还原

【Abstract】 Sandstone acidizing is one of the most widely used stimulation methods for oil or water injection well.For the purpose of the removal of damage caused by drilling, completion, production and water injection operations, the skin factor of well test analysis is usually adopted to evaluate the damage condition of a particular well.However, field practices and some analysises presented in this dissertation suggested some restrictions of well test analysis when a design of damage removal treatment is needed. These restrictions results in that we can’t get a detailed information of the damaged well which is critical to the designing of acidizing.To solve this problem, a method of determining the major and minor damage factors of a particular well by quantitative analysis was put forward, which makes up for the defects of well test analysis and ensures the optimization of the design of damage removal treatment.The core of the new method is to determine the respective influence of all damage factors existing in a particular well. On the basis of the analysis of formation damage from both internal and external aspects, several damage mechanisms commonly occurring in a producer or injector were modeled. These mechanisms included the plugging of drilling solids and filtration, particle migration, clay hydration and swelling, organic and inorganic scaling as well as the plugging of solids and bacteria in a water injection well. With these models, the damage skin and the radius of the damage zone caused by various factors could be diagnosed accurately.Besides, the influence of damage on a horizontal well was considered by a study of the calculation of damage skin factor. Comparison of two model indicated that model of Furui-Zhu-Hill is more reasonable.With the knowledge of the major and minor damage factors, various special damage removal techniques for different damaging materials are studied in order to treat the damaged well suiting the remedy to the case. In combination with the optimizing object of the removal of damage zone , the design of acidizing in a sandstone formation is simulated.To gain a better result of stimulation, the potential damage that may be introduced by the treatment must be precautioned or reduced minimally.Based on the models involved, the diagnosis of the damage done to a well and the design of acidizing were programmed. Case studies were given and some instructiveconclusions were drawn.更多还原