【作者】 陆程；

【导师】 王晓冬；

【作者基本信息】 中国地质大学（北京） ， 油气田开发工程， 2010， 硕士

【摘要】 水平井是开发油气田的一种有效手段。大庆油田长垣老区依靠水平井泄油面积大、能够有效地抑制底水上升、提高采收率、节约钻井投资等技术优势,利用水平井挖潜中高渗油藏厚油层顶部剩余油,开拓了水平井应用的一个新领域。但是,它所引起的油藏工程问题比较复杂。本次论文以此为研究背景,旨在开展对水平井底水脊进问题进行研究。首先,根据静水力学理论,分析得到了水脊的形成机理并确定了水脊稳定的条件。其次,结合平面径向稳态渗流理论确定底水地层中水平井流线分布、水脊突破时间、水平井临界产量、水平井临界长度、底水驱替效率以及水脊形状等并进行了分析:(1)通过流函数计算得到了水平井底水脊进的流线分布。分析得知对于底水油藏,油层越薄底水流线分布越尖锐,油层越厚流线分布越平缓,当油层厚度无限大时底水流线分布趋近于边水情形。(2)通过势函数计算得到了水脊形成过程中水脊顶点运动规律。分析得知水脊形成过程中,水脊顶点运动速度是递增的,越接近水平井筒速度越快,因此控制水脊的形成在开采早期就应当重视。另外,还分析了对于特定的无量纲水脊突破时间,垂向渗透率与水脊突破时间成反比,垂向渗透率越大突破时间越短;油层厚度与水脊突破时间成正比,油层越厚突破所需要的时间约长。(3)在层流范围内,产量高的水平井底水水脊是较平缓的(这时水平井笼统见水),而产量较低的水平井底水水脊是较尖的(这时水平井中部见水)。当水平井产量极高时,受水平井筒管流影响,见水部位将向水平井根端偏移。(4)不考虑井筒管流影响下,底水驱替效率伴随着水平井长度的增加而增加。而考虑井筒管流影响下,驱替效率在水平井长度增加到一定值时表现为一个常数。在理论分析基础上,选取研究区典型井进行实例分析,为老区外围特高含水期在厚油层顶部部署水平井提供了合理化建议。更多还原

【Abstract】 Horizontal well is effective in exploiting field, which can bring all advantages into full play, such as larger drainable area, control bottom water rising, improve flat connectivity remarkably, enhanced oil recovery, save invest for well drilling. In high permeability reservoir, remaining oil at the top of thick oil layer has been exploited by horizontal well in the old liberated area of Changyuan Daqing city, which developed a horizontal well applied frontier. But it brought complicated reservoir engineering problems. We chose the area as research background and researching for bottom water coning in horizontal well.First of all, based on hydrostatics theory, analyzed formation mechanism and defined stable conditions of corning. By combining it with flat radial direction time invariant seepage theory can define streamlines distribute, breakthrough time, critical produce, critical length, bottom water’s displacement efficiency and shape of coning in bottom water layers. Reveals the following regularities:(1) After calculating the streamlines distribution of horizontal well bottom water coning by stream function. For bottom water reservoirs, We can find that the smaller reservoir thickness is, the keener bottom water streamlines distribution are, vice versa. If the reservoir thickness is infinity, bottom water streamlines distribution approach edge water case.(2) We can got the peak moving regular of water coning by potential function. The movement velocity of peak is incremental in coning water formation process, the closer to horizontal well borehole, the faster it is. It is important to control coning at the early phase. At particular time, vertical permeability is inversely proportional to water coning time, the smaller it is, the longer breakthrough time is. Reservoir thickness and water coning time in direct proportion, the bigger reservoir thickness is, the longer breakthrough time is.(3) For laminar flow, water ridge of horizontal well which is large duty and longer is flat (at this time, the whole horizontal well breakthrough), water ridge of horizontal well which is low duty and shorter is aciculate (at this time, the middle part of horizontal well breakthrough). If the horizontal well has very high output, the affect of borehole tube current are larger, the place of breakthrough will deviate to heel.(4) With horizontal well length increasing, displacement efficiency function will add (not think about borehole tube current). With well length reach a specified value and thinking about borehole tube current, displacement efficiency function will to be a constant.Based on theoretical analysis, we chose the canonic well as an example to be analyzed, which can offer innovation to high water cut stage horizontal well disposition at the top of thick oil layer in old liberated area outer-ring.更多还原