基于井温的超深断溶体油藏油井动用深度计算

超深断溶体油藏纵向连通性好,油井生产时井底下方油气易沿断裂高导流通道向井底流动。为明确油井油藏动用深度,以Z油田W9井为例,对比分析超深断溶体油藏流温、静温特征,并基于温度特征建立不同温度-深度关系下油井动用深度计算方法。研究表明:同一深度下流温大于静温,与油嘴直径无关;当深度一定时,油嘴直径越大,流温越高;随深度增大,流温与静温差整体呈降低趋势,靠近井底处流温梯度较低;超深断溶体油藏温度特征受热损失、油井动用深度和传热方式影响;W9井在目前4.5 mm油嘴生产条件下动用深度约为52～62 m。该研究可为超深断溶体油藏油柱高度判断、储量计算、合理生产制度的制订提供依据。

Calculation of Production Depth of Oil Wells in Ultra-Deep Fault-Karst Reservoirs Based on Well Temperature

Due to good vertical interconnection in the ultra-deep fault-karst reservoirs, oil and gas under the well bottom can easily flow to the well bottom along the fractured channel with high conductivity in oil well production. In order to identify the production depth of oil wells, Well W9 well in Z Oilfield was taken as an example to compare and analyze the characteristics of flow temperature and static temperature of ultra-deep fault-karst reservoirss, and establish the calculation method of oil well production depth with different temperature-depth relationships based on temperature characteristics. It was found in the study that the flow temperature at the same depth was greater than the static temperature, which had nothing to do with the nozzle diameter; when the depth was constant, the larger the nozzle diameter, the higher the flow temperature; as the depth increased, the difference between the flow temperature and the static temperature generally decreased, and the flow temperature gradient was low near the well bottom; the temperature characteristics of the ultra-deep fault-karst reservoirs were affected by heat loss, oil well production depth and heat transfer mode; the production depth of Well W9 was about 52 to 62 m under the current production conditions with Ф4.5 mm nozzle. This study can provide a basis for the judgment of oil column height, reserve calculation and formulation of reasonable production systems for ultra-deep fault-karst reservoirs.