Horizontal Well Testing of Isolated Segments
Horizontal Well Testing of Isolated Segments
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DOI：
10.2118/29959-pa
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发表时间：
1996-09
期刊：
影响因子：
3.6
通讯作者：
T. Frick;C. Brand;Bernhard Schlager;M. Economides
中科院分区：
文献类型：
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作者：
T. Frick;C. Brand;Bernhard Schlager;M. Economides
在大储层和小井筒存储中的水平井测试应该产生某些不同的流动状态。这些应导致对三种渗透率（沿着、垂直于井眼轨迹）、总井表皮效应以及可能的有效（开口）井长的估计。这项工作的目的是优化试井设计，以获得所需的流态。结果表明，重要的早期流动状态可以被井筒储存效应所掩盖。因此，应通过使用井下关井来最大限度地减少续流。贮存效应可用经验公式估算。这些关系也标志着第一个可解释的流态的开始。研究表明，对于非常薄的地层或在靠近顶部或底部边界钻井的情况下，可能根本看不到早期的径向流态。几乎完全横向穿透的水平井的长度也可能扭曲后期径向流。在这两种情况下，控制渗透率的计算变得困难甚至不可能。因此，可能期望测试井的较小区段。在对另一个管段进行流量测试期间，在一个孤立的管段中放置一个观测仪表可以提供更多的信息。结果表明，在观察规的压力响应的导数表现出一个特征驼峰。当出现驼峰时，可以计算出沿井轴沿着方向的渗透率。对隔离段的测试还将提供沿延伸水平井沿着的表皮分布的详细图像。从这样的测试中，可以得出有价值的信息，为加强刺激和选择完井设计。
A horizontal well test in a large reservoir and with small wellbore storage should produce certain distinct flow regimes. These should lead to the estimation of three permeabilities (along, normal and vertical to the well trajectory) the total well skin effect and, perhaps, the effective (open) well length. The objective of this work is to optimize well test design to obtain the desired flow regimes. It is shown that the important early-time flow regimes can be masked by wellbore storage effects. Therefore, afterflow should be minimized by using downhole shut-in. The storage effects can be estimated with empirical equations. These relationships also mark the beginning of the first interpretable flow regime. It is shown that for very thin formations or in situations where the well is drilled close to the top or bottom boundaries the early radial flow regime may not be seen at all. The length of an almost fully laterally penetrating horizontal well may also distort the late-time radial flow. In both of these instances, calculation of the controlling permeabilities becomes difficult to impossible. It may thus be desirable to test smaller segments of the well. Placing an observation gauge in an isolated segment during the flow testing of another segment can provide further information. It is shown that the derivative of the pressure response in the observation gauge exhibits a characteristic hump. When the hump appears, the permeability along the well axis can be calculated. Testing of isolated segments would also deliver a detailed picture of the skin distribution along an extended horizontal well. From such a test valuable information for enhanced stimulation and selective well completion design can be drawn.