喇萨杏油田薄差油层及表外储层调整方式

ADJUSTMENTS ON THIN AND POOR RESERVOIR AND UNWORKABLE RESERVES IN LA-SA-XING OILFIELD

喇萨杏油田已进入特高含水期及高采出程度开发阶段，多油层、非均质严重，薄差油层及表外储层储量占30％以上，这类油层不仅具有低渗透油层的特点，而且与中高渗透油层交互分布，开采及调整难度大。通过对喇萨杏油田薄差油层及表外储层分布特点、开发现状及剩余油分布的分析，提出了与油层性质相结合、与剩余油分布相结合、与原井网布井方式相结合、与长远调整方式相结合的原则。结合二类油层上返时机及多套层系开发的特点，充分利用三次加密、三次采油相结合调整方式，三次加密井水驱调整与现井网注采系统调整方式，发展和完善现有开发技术，选择合适的油层组合方式、井网井距及驱替方式，提高薄差油层及表外储层的动用程度。

La-Sa-Xing Oilfield has already entered ultra-high water cut and high recovery stage, with existence of multiple oil-bearing layers and severe heterogeneity, where the thin and poor reservoirs and unworkable reserves take 30% of the total reserves, not only are the reservoirs of low permeability, but also high permeable and medium permeably layers alternatively cross bed each other, which make production and adjustments hard to be conducted. To fully recover the potential of poor reservoirs and unworkable reserves, the reservoir properties, remaining reserves distribution, coherence with the former well pattern, and long-term development should all be considered and integrated as the guideline for adjustments. Regarding the features of thin and poor reservoirs and unworkable reserves, and considering the timing to produce Type-Ⅱ reservoirs from bottom to top, as well as features of multiple layer series development, using adjustment of third-round of infill and EOR combination, water flooding adjustment of third-round of infill wells and injection-production system adjustment under current well pattern, existing evelopment technologies should be innovated and improved. Layers combination, well spacing and drive mechanism should be reasonably decided to enhance the recovery of poor reservoirs and unworkable reserves.