Improved DTS profiling model for horizontal gas wells completed with the open-hole multi-stage fracturing system
Improved DTS profiling model for horizontal gas wells completed with the open-hole multi-stage fracturing system
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DOI：
10.1016/j.jngse.2020.103642
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发表时间：
2020-10
影响因子：
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通讯作者：
W. Sui;Di Zhang;Si Cheng;Qilin Zou;Xiaosong Fu;Zehao Ma
中科院分区：
文献类型：
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作者：
W. Sui;Di Zhang;Si Cheng;Qilin Zou;Xiaosong Fu;Zehao Ma
将光纤分布式温度传感器应用于水平多段压裂威尔斯井的流动剖面分析，建立了多段压裂水平井的储层/井筒耦合热模型。虽然这些理论模型只适用于某些特定的场景，但业界已经意识到了非常规资源产量预测的巨大潜力。本文介绍了一个致密气藏水平多级压裂井裸眼封隔器完井情况下的渗流剖面计算实例，应用一种新的改进的理论模型，扩展了传统的半解析井筒-裂缝-储层耦合渗流/热模型，该模型已发展用于套管井、射孔井和多级压裂威尔斯井，考虑裸眼封隔器完井方案的特殊性。由于地层流体首先通过裂缝流入地层和生产尾管之间的裸眼环形空间，然后沿着环形空间流动直到遇到生产管上的压裂端口，因此增加了模拟子区域来表示裸眼环形空间，该模型成功地模拟了两种不同的流动和传热过程，在环形空间和生产管道中同时流动和传热所引起的分段流态。在每个阶段，如果裂缝和压裂口位置不一致，则压裂温度数据可能会出现由于焦耳-汤普森冷却效应而导致的双降现象。然后对鄂尔多斯盆地某水平多级压裂井三流量试采过程中的动态监测数据进行了模拟分析。模拟中考虑了裸眼封隔器完井的影响，预测结果令人满意。
The fiber-optic distributed temperatrue sensor (DTS) has been used for flow profiling in horizontal multi-stage fractured wells, and several reservoir/wellbore coupled thermal models were developed. Although these theoretical models are applicable only to some specific scenarios, the industry has realized the great potential of DTS for production prediction in unconventional resources. This paper presents a DTS flow profiling case for a horizontal multi-stage fractured well in tight gas reservoirs with open-hole packer completion scenarios by applying a newly improved theoretical model.In this paper, we extended the conventional semi-analytical wellbore-fracture-reservoir coupled flow/thermal model which have been developed for cased, perforated, and multi-stage fractured wells, by considering the special feature of the openhole packer completion scenario. Since the formation fluid flows first through the fracture into the open-hole annular space between the formation and the production liner, and then flow along the annular space until meeting the frac port on the production pipe, a simulation sub-region was added for representing the open-hole annular space, which helps to understand the flow and heat transfer inside it. The presented model successfully simulated the two-segment flow regime caused by the simultaneous flow and heat transfer in the annular space and the production pipe. In each stage, the DTS temperature data possibly show double drops due to the Joule-Thompson cooling effects at the fractures and frac ports if their locations are not consistent.With the improved model, the synthetic cases were firstly used for studying the temperature characteristics and the effects of gas production rate and frac port location. Then the DTS monitoring data during a three-rate production test in a horizontal multi-stage fractured well in the Erdos Basin of China was simulated and analyzed. The open-hole packer completion was taken into account in the simulation and the gas rate prediction is satisfactory.