周期注水在萨北开发区水驱中的研究与应用

发布时间：2019-07-03 13:40

【摘要】：萨北开发区针对特高含水期开发实际，，加强了水动力学方法的研究与应用，在实践中取得了较好的效果。周期注水是指通过改变注水井注水时间和方式，在油层里建立起一种不稳定的动态变化，改善油田的开发效果。目前大庆油田萨北开发区已经进入特高含水后期开采，油田含水上升速度减缓，但是随着可采储量的逐渐减少，液油比上升速度加快，常规的油水井措施效果越来越差，挖潜效果远不如初期，且受工艺和经济条件限制，进一步提高注水井注水的地下波及体积难度较大。因此，在这种形势下如何进一步控制含水上升，增加可采储量，延缓产量递减，是现阶段改善开发效果，提高经济效益的重中之重，而周期注水则是被证明在此阶段是很经济有效的手段。萨北开发区的三套开发层系是大庆长垣中部的含油组合萨、葡、高油层，葡萄花发育大型河道砂，为主力油层，萨尔图的部分油层连通性好，厚度大，也为主力油层，其余皆为非主力油层，如此分类便于开发中的调整。这三套油层组主要属于松辽盆地北部沉积体系的大型叶状三角洲沉积，部分属于泛滥平原下游的大型河流沉积。整个地区的结构较为稳定，湖泊水域的遮盖面积较为广阔。周期注水机理就是通过改变注水井工作制式，工作时间，在非均质油藏的纵向上层段间形成附加的压力差，并生成追加窜流。这个追加窜流能起到均匀油层纵向水淹的作用，有利于开发效果的改善，并且稳定条件下层段间渗透率和饱和度差异越大，矛盾越突出，周期注水效果越明显。随着渗透率和饱和度差异的增大，层段间产生的附加压力差就越大，于是在周期注水一个周期内由好层向差层渗透流动的水量就越多，反向流动的油量也就越多，反映到指标上就是含水的上升速度减缓甚至含水下降，减少低效无效循环，改善开发效果。针对纯油区和过渡带的不同发育方式分别分析制定实验，数值模拟，得出最合理的周期时间和方式。停层不停井方式，特别是停注好层段，保持甚至加强差层注水，实际上好层的高受到周期注水的效果，剩余油得到驱动渗出，而差油层则改善吸水剖面，原本不吸水的层段开始吸水，层间矛盾得到缓解，以此控制了含水的上升速度，减少低效无效循环。纯油区与过渡带发育上存在一定差异，尤其是过渡带的四条带，发育上差异更大。周期注水在纯油区的实施方式方法与在过渡带四条带相应层位上的方式方法有所不同。通过实验和数值模拟相结合分析得出合理的周期注水周期，注水压力等技术参数界限，提高区块采收率，减缓含水上升速度。本论文最终得出结论，在油田中低含水斯周期注水的停注时间应控制在3个月以内，在中高含水期则应控制在2个月以内在40天左右为最合适，而实际应用中发现，对于含水过高的过渡带而言，可以适当将停层不停井这种周注方式的实施半周期加长，其对产油的影响在60天以上时才逐渐明显，全井停则控制在50天以内效果最好。采用层段同步周期注水方法，油层始终保持注水，避免了地层压力大幅度波动，使得油田开发状况保持稳定，是高含水后期改善水驱开发效果的有效方法。周期注水方式的选择及工作制度的确定，要结合区块的地质特点开发状况合理组合，要充分考虑纵向上平面上矛盾，结合油层发育状况，注采对应关系，层系间的相互影响。油田在目前的开发条件下，应充分利用现有层系和井网，通过周期注水调控压力场，提高注入水的利用率，使滞留状态的原油运用起来。油层改造措施要寓于压力场调整之中，全方位地提高各类储层的运用程度。
[Abstract]:The research and application of the method of water dynamics have been strengthened for the development of the high water cut stage in the Sanbei Development Zone, and the better effect has been achieved in practice. The period water injection is a kind of unstable dynamic change in the oil layer by changing the water injection time and the way of the injection well, and the development effect of the oil field is improved. At present, the Sabei Development Zone of Daqing Oil Field has entered the later stage of the high water cut, and the water rise speed of the oil field is slowed down, but with the gradual decrease of the recoverable reserves, the liquid oil is faster than the rising speed, and the conventional oil well measures are getting worse and worse, and the potential for excavating the oil well is not as good as the initial stage. And the underground wave and the volume difficulty of the water injection of the water injection well are further improved. Therefore, in this situation, how to further control the water-bearing rise, increase the recoverable reserves, and delay the decline of the output, it is the most important to improve the development effect at the present stage and to improve the economic benefit, and the periodic water injection is proved to be a very economical and effective means in this stage. The three development layers of the Sabei Development Zone are the oil-bearing composition of the central part of the Daqing Changs, and the large-scale river sand is developed in the high oil layer and the high oil layer. The main oil layer and the part of the oil layer of the Sartu are well connected, the thickness is large, the main oil layer is the main oil layer, and the rest are non-main oil. a layer that is so classified as to facilitate the modulation in development The three sets of oil layers mainly belong to the large-scale, leaf-type delta deposition of the sedimentary system in the northern Songliao basin, and some of them belong to the large-scale river sedimentation in the downstream of the flood plain. The structure of the whole area is more stable, and the covering area of the lake water area is wide The mechanism of the period water injection is to change the working system and working time of the water injection well, to form an additional pressure difference between the longitudinal upper sections of the heterogeneous oil reservoir and to generate the follow-up The addition of the blowby can play a role in the longitudinal flooding of the uniform oil layer, which is beneficial to the improvement of the development effect, and the higher the permeability and the saturation difference between the lower section of the stable condition, the more the contradiction is, the effect of the periodic water injection the more obvious the difference in permeability and saturation, the more the additional pressure difference generated between the layers, the more the amount of water that the good layer can penetrate through the good layer to the differential layer during one cycle of the periodic water injection, and the amount of the reverse flow The more it is, it is reflected in the indicator that the rising speed of the water is slowing down and even the water content is down, reducing the inefficient and inefficient cycle, improving the opening, The results show that the most reasonable period is obtained for the different development modes of pure oil and transition zone. time and mode. The stop-layer continuous well mode, in particular to stop the good layer section, maintain or even strengthen the water injection of the differential layer, in fact, the high layer is subjected to periodic water injection, the residual oil is driven to ooze, and the poor oil layer improves the water absorption profile, and the original water-absorbing layer section starts to absorb water and the interlayer spears The shield is relieved to control the rate of water rise and to reduce The effect is not effective. There are some differences in the development of the pure oil region and the transition zone, especially the four bands in the transition zone. The difference is greater. The method of the cyclic water injection in the pure oil area and the way on the corresponding horizon in the four zones of the transition zone The method is different. Through the combination of the experiment and the numerical simulation, the reasonable period, the water injection pressure and other technical parameter limits are obtained, and the recovery rate of the block is improved and the content of the water is reduced. The paper concludes that the time of the water injection in the low water-bearing period of the oil field should be controlled within 3 months. In the medium-high water-cut period, it should be controlled to be the most suitable for about 40 days within 2 months. In the practical application, it is found that for the water-bearing In the case of high transition zone, the half-cycle of the continuous injection method of the stop layer can be lengthened appropriately, and the effect on oil production is gradually obvious when the effect on oil production is more than 60 days, and the whole well is controlled at 50 The effect is best within the day. By adopting the method of layer-section synchronous period water injection, the oil layer is always filled with water, so that the formation pressure is greatly fluctuated, so that the development condition of the oil field is stable, and the water drive development is improved in the later stage of the high water cut. The effective method of the effect is as follows: the selection of the periodic water injection mode and the determination of the working system, and the reasonable combination of the geological characteristics and the development condition of the block, taking full consideration of the contradiction in the longitudinal upper plane, combining the development condition of the oil layer, the corresponding relation between the injection and production, the layer, In the present development condition, the oil field should make full use of the existing layer and well network, control the pressure field through periodic water injection, increase the utilization rate of the injected water, and make the retention state The oil layer modification measures should be incorporated in the pressure field adjustment, and all kinds of oil layer modification measures should be improved in all directions.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.6

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