Abstract: This paper focuses on the geological characteristics of low-permeability oil reservoirs, such as small pore throats, difficult movement of fluids, low porosity and low abundance, as well as the development characteristics, such as natural productivity of oil production wells and poor capability of water injection wells for absorption of water. Based on the conditions of offshore oilfield development, the paper studies a series of problems of offshore low-permeability oil reservoir development, such as extreme injection-production well pattern, horizontal sweep efficiency and vertical producing degree, and injection-production balance. It also makes analysis of three basic contradictions facing offshore low-permeability oilfield development ---the contradiction between “using less wells for development” and “effective injection and production”, the contradiction between “high-efficiency production” and “low sweep efficiency” and the contradiction between “high-efficiency development” and “injection-production imbalance”. The main controlling factors of those contradictions can be attributed to a few development wells ofoffshoreoilfields becauseoftheoffshoreenvironment and high production cost.Withthestudyof the orientationtomake technological breakthrough, the paper points out that the efforts should be focused on improvement of single-well production and reduction of allocation in single-well engineering investment while exploring a new pattern for effective development in the areas of well type, well pattern and injection-production style.

Key words: offshore, low-permeabilityoilfields, developmentcontradiction, controlling factors

摘要： 根据低渗透油藏储层孔喉细小、流体流动困难、孔隙度低、储量丰度较低等地质特点,以及采油井自然产能低、注水井吸水能力差等开发特点,针对海上油田的开发条件,研究了海上低渗透油藏开发的极限注采井距、平面波及系数和纵向动用程度、注采平衡等问题,分析了海上低渗透油藏开发所要解决的三个基本矛盾,即"少井开发"与"建立有效注采"的矛盾、"高效动用"与"波及程度低"的矛盾、"高速开发"与"注采不平衡"的矛盾,指出矛盾产生的主控因素是海上油田开发井少,导致原因是海洋环境和开采高成本。在此基础上,研究了实现海上低渗透油藏有效开发的技术突破方向,指出应从提高单井产量、降低单井工程投资分摊两方面入手,在井型井网和注采方式上探索有效开发新模式。

关键词: 海上, 低渗透油田, 开发矛盾, 控制因素