【作者】 钱杰；

【导师】 冯文光； 齐振林；

【作者基本信息】 成都理工大学 ， 油气田开发工程， 2006， 博士

【副题名】以萨尔图中部开发区北一二排西部上返区块为例

【摘要】 自二十世纪九十年代后期以来，大庆油田进入高含水、高成本、高难度开发阶段，主力油层又无剩余可注聚合物驱油区块，“十一五”期间油田后备潜力不足，接替稳产潜力变小，在此背景下探索北一二排西部区块主力油层结束三次采油开发后上返到二类油层进行工业化聚合物驱油，以实现油田产量的接替与持续发展。 北一二排西部位于大庆油刚萨尔图中部开发区北部，含油面积7.0km²，于2002年1月结束主力油层开发上返到二类油层萨Ⅱ10～萨Ⅲ10单元层，2003年12月上返区块油水井208口全部投产。上返目的层属于一套河流～三角洲沉积体系，共有20个沉积单元层，沉积砂体类型有主河道砂、决口水道砂、河间砂、河间淤泥、水下分流河道砂、三角洲内前缘相席状砂等。由于油层发育的非均质性导致上返层在水驱开发阶段水淹不均匀和剩余油分布的不均匀，从而为聚合物驱油奠定了物质基础。 聚合物溶液是非牛顿流体，它具有特殊的流变性：低速下呈剪切变稀流变性；超过一定流速后呈胀流性特征；若速度很大，会使聚合物发生剪切降解。聚合物溶液在二类油层中的驱油规律基本与主力油层既有相同点，又有差异。比如聚合物用量、浓度、一定范围内分子量增加驱油效果随之增加。但二者油层物理性质上的差异，在聚合物驱油过程中又表现出不同之处：油层渗透率、孔喉半径值及其分布的不同特点，使二类油层更适宜采用有别于主力油层的宽分子量分布的中分子量聚合物驱油，有利于减少油层中的不可及孔隙体积，提高驱油效果；二类油层中中等分子量聚合物在0.6～6m／d流速范围呈现粘弹性流变特性，1000ppm聚合物溶液驱油毛管数为10^-4～10^-3，大于水驱油的毛管数，因而具有比水驱提高驱油效率的能力；二类油层吸水能力较差适宜采用的聚合物分子量、注聚速度、浓度相对受限，驱油效果差于主力油层，最终采收率较主力油层低3～5个百分点。 通过对二类油层聚合物驱油特性、规律研究，优化设计大庆油田首个二类油层工业化聚合物驱油方案参数，并利用分层注聚技术、深度调剖技术提高聚合物驱油效果，并通过方案实施后的跟踪、观察认识到：二类油层聚合物驱油相对于主力油层具有见效井出现时间晚、见效井含水下降百分点高、相同聚用量下增更多还原

【Abstract】 Since the 1990s, Daqing oilfield entered a new development stage of high water-cut, high cost and high development difficulty. There is less residual oil remaining in conventional productive reservoirs, thus an inadequate oil reserve as well as a lower productivity prospect is seen in the period of the eleventh five year plan. Under this condition, we performed a research in eastern N-1-2P block, where tertiary recovery failed to produce sufficiently and we have to move industrialized polymer flood up to the poor and thin layers, so as to ensure a desirable production rate and a sustainable oilfield development.The N-1-2P block lies in the north of the Sartu oilfield, Daqing. It covers an oil containing area of 7 km2. In January 2002 tertiary recovery ended in the conventional productive reservoirs and went up to the poor and thin layers of Sa II10-Sa III10. A total number of 208 wells including producers and water injectors were put into production in December, 2003. Its target layer is a series of fluvial and deltaic deposited reservoir, containing 20 deposited single layers. The deposited sandstone style including fluvial channel sand, crevasse channel sand, interstream sand, interstream silt, under water distributary channel sand, delta front sheet sand and etc. Since the reservoir heterogeneity usually result in irregular water flooding and irregular residual oil distribution during the water flood development period, where is regarded as the poor and thin layer compared with the conventional productive reservoir, thus provide a substantial basis for polymer flood.Polymer solution is a kind of non-newtonian fluid with a specific rheological property. Polymer solution shows a shearing and thinning rhelogical property under low flow velocity; it shows a swelling property at a certain higher flow velocity; if the flow velocity is trmendously high, it shears and degrades polymer solution. Polymer solution in poor and thin layers acts similar as how it performs in the conventional productive reservoirs. For example, a certain degree of increase in polymer quantity, concentration and molecular weight will produce more oil. Since the different physical properties in the conventional productive reservoirs and the poor and thin layers, polymer solution performs differently in the course of polymer flood. Reservoir permeability, pore throat and its distribution make it more feasible to use medium molecular weight in poor and thin reservoirs, it is hopeful to sweep more pore volume and improve oil recovery. In the poor and thin layers, the medium molecular weight shows an visco-elasticity rhelogical property at the flow velocity of 0.6-6m/d. For the 1000ppm polymer solution, its capillary number is 10-4-10-6, higher更多还原