塔河托甫台区奥陶系油井产量突降研究

发布时间：2018-04-04 12:37

本文选题：托甫台区　切入点：开发动态　出处：《成都理工大学》2015年硕士论文

【摘要】：油井在开发过程中,随着地下流体的不断采出,剩余储量不断减少,油藏能量不断下降,日产油量总是下降的,油井在结束一段时间的稳产期后,后期产量必然会进入递减阶段,不同生产阶段表现的递减特征有所不同。通过研究油井的产量递减特征,把油井划分为4种基本类型:高产稳产型、低速递减型、中速递减型和快速递减型。然而在塔河油田托甫台区奥陶系油藏的实际开发中发现,部分油井在产量递减阶段,出现了日产油量较高时突然大幅降低至停喷的产量突降异常现象,这在一定程度上影响了托甫台区油藏的开发,因此需要对这一现象进行综合分析,以便科学合理地指导油田开发。本文依据托甫台区奥陶系碳酸盐岩油藏的基本地质特征及开发现状,基于储集空间的特征识别,结合油井的地震、钻完井、测录井、动态监测、开发动态以及产量突降后的开发措施等资料,对9口产量突降井的储层类型和特征、开发动态特征以及产量变化的控制因素等方面进行了分析,主要从地层能量、溶解气相态、储层物性、含水特征、采油制度及井间连通性几个方面研究了产量突降的原因,明确了影响油井产量变化的控制因素,根据不同的产量突降原因提出应对的开发对策,最终得出以下几点认识:(1)根据托甫台区奥陶系油井自喷生产过程中产量和压力的变化特征,将9口产量突降井分为3类:产量为中高产且较稳定,压力缓慢下降;产量为中高产,缓慢下降,压力缓慢下降或较快下降;产量不稳定,下降较快或间歇生产,压力快速下降,自喷期极短。以上三类开发动态特征分别对应的储集空间为:边底水活跃的较大型缝洞单元;中小封闭型缝洞单元;规模较小且充填程度较高的缝洞单元。(2)经研究得出托甫台区奥陶系油井产量突降的原因有五种:能量亏空、原油脱气、储层污染、含水快速上升、初期采油速度过高。(3)影响油井产量变化的地质因素有:储层类型、溶洞充填程度、地层能量、含水上升、原油脱气程度、储层污染程度等;影响油井产量变化的工程因素有:工作制度、采油速度、采油工艺等。实际上产量变化往往不是由某个单一因素决定的,而是上述多种因素共同作用的结果。(4)针对不同的产量突降原因提出合理的开发对策:由于能量亏空和原油脱气导致的产量突降,建议在压力下降到较低程度前进行注水,以保持油井压力,恢复地层能量。由于储层污染造成的产量突降,建议在突降后对油井进行酸压改造解堵,改善井底渗流通道,提高渗透率,从而恢复供液能力。由于含水快速上升导致的产量突降,可以通过平面调整及周期注水改变液流方向和压力场,从而改变水线推进状况;或者关闭高含水井,封窜及封堵油井高含水层;注水井调剖和调整注水结构等措施预防含水上升。由于初期采油速度过高导致的产量突降,应合理控制采油速度,保持较长时间的自喷生产。
[Abstract]:In the process of oil well development, with the production of underground fluid, the remaining reserves are decreasing, the reservoir energy is decreasing, and the daily oil production is always decreasing.The late stage of production will inevitably enter the stage of decline, different production stages show different characteristics of decline.By studying the characteristics of oil well production decline, the oil well can be divided into four basic types: high and stable production type, low speed decline type, medium speed decline type and fast decreasing type.However, in the actual development of Ordovician reservoirs in Tauphoutai area of Tahe Oilfield, it is found that in the stage of production decline, some oil wells have suddenly and substantially reduced their daily oil production to a sudden drop when the daily oil production is relatively high.This has affected the development of reservoir in Tofoutai area to some extent, so it is necessary to analyze this phenomenon comprehensively in order to guide the development of oil field scientifically and reasonably.According to the basic geological characteristics and development status of Ordovician carbonate reservoirs in Tofoutai district, this paper is based on the recognition of reservoir space, combined with the seismic, drilling and completion of oil wells, logging, dynamic monitoring, and so on.In this paper, the reservoir types and characteristics of 9 production sudden drop wells, development dynamic characteristics and controlling factors of production change are analyzed in terms of formation energy, dissolved gas phase, and so on.The reservoir physical properties, water cut characteristics, oil recovery system and inter-well connectivity are studied in this paper, and the factors controlling the change of oil well production are defined, and the corresponding development countermeasures are put forward according to the different reasons for the sudden drop of oil production.Finally, according to the characteristics of production and pressure of Ordovician oil wells in Tofoutai district, 9 wells are divided into three categories: medium high yield and stable production, and pressure decreasing slowly;The yield is medium and high yield, slowly decreasing, pressure decreasing slowly or rapidly, and the yield is unstable, falling quickly or intermittently, the pressure drops rapidly and the period of self-spraying is very short.The reservoir space corresponding to the dynamic characteristics of the above three types of development is as follows: larger fracture-cavity units with active edge and bottom water, small and medium-sized closed fracture-cavity units, and small and medium-sized closed fissures and caverns.On the basis of research, it is found that the production of Ordovician oil wells in Tofoutai area has five causes of sudden decline: energy deficit, crude oil degassing, reservoir pollution, and rapid increase of water cut.The geological factors affecting the oil well production change are: reservoir type, cavern filling degree, formation energy, water cut rising, crude oil degassing degree, reservoir pollution degree, etc.The engineering factors that influence the change of oil well production are: working system, oil recovery speed, oil recovery technology and so on.In fact, yield changes are often not determined by a single factor,It is the result of the combined action of the above factors. (4) A reasonable development countermeasure is put forward in view of the different reasons for the sudden drop in production: due to the energy deficit and the sudden drop of the output caused by the degassing of crude oil, it is suggested that water injection should be carried out before the pressure drops to a lower level.To maintain the well pressure and restore formation energy.Due to the sudden drop of production caused by reservoir pollution, it is suggested that acid-pressure modification should be carried out to remove the plugging of oil wells after sudden drop, to improve the percolation passage under the well and to increase the permeability, so as to restore the fluid supply capacity.Due to the sudden decline of production caused by the rapid rise of water cut, the direction of fluid flow and pressure field can be changed by plane adjustment and periodic injection, thereby changing the waterline advancing condition, or closing the high water cut well, sealing and sealing the high aquifer of oil well;Water injection well profile control and water injection structure adjustment and other measures to prevent water cut rise.Since the initial oil production rate is too high, the production rate should be controlled reasonably and the self-injection production should be maintained for a long time.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE328

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