海上油田非均衡化学驱理念、模式及先期实践

海上油田储层非均质性较强,水驱后不论层间、层内,还是微观,都存在常规水驱技术手段难以高效动用大量剩余油的问题.为使油藏的驱替效果最大化,提出了一种适合海上油田特点的非均衡化学驱理念及模式,该模式针对储层4个层次的非均质性:层间非均质性、层内非均质性、平面非均质性以及微观非均质性,采取相应的非稳定、非连续、非均相与非对称的技术手段,最大限度地实现纵向和平面均衡驱替目的,并在海上J油田开展了非均衡化学驱模式的先期实践.结果表明,两口中心井明显见效,其中一口井含水由84.6％下降至70.2％,日产油提高70％;另一口井含水率由96.1％下降至88.0％,日产油提高173％,均取得了显著的技术经济效果.证明了该模式的可行性和有效性,适合海上的储层流体性质和开发特点,有望成为海上油田提高采收率的主要发展方向之一.

The concept, pattern and pilot test of non-equilibrium chemical flooding in offshore oilfields

The reservoir heterogeneity of offshore oilfield is very serious, and the residual oil still exists between and within layers after water flooding, which is difficult to be displaced efficiently. However, in order to maximize the oil displacement effect of reservoir, the pattern of non-equilibrium chemical flooding, which is suitable for offshore oilfield, is proposed in this paper. Aiming at the interlayer, intra-layer, plane and micro-heterogeneity, this technology adopts the corresponding unsteady, non-contiguous, dispersed and asymmetric technical means, in order to achieve the goal of vertical and horizontal equilibrium displacement. Furthermore, its field trial in offshore J oilfield has been carried out. Results show that, the water cut of one central well decreased from 84.6% to 70.2%, and the daily oil production increased by 70%; and the water cut of the other central well decreased from 96.1% to 88.0%, and the daily oil production increased by 173%, which both have achieved remarkable technical and economic results. Therefore, its feasibility and validity has been proved by the field application, and it is suitable for the reservoir fluid properties and development characteristics in offshore oilfield. As a result, the non-equilibrium chemical flooding pattern is the development direction of enhancing oil recovery in offshore oilfields.