论文部分内容阅读
在北海一水平井中对某储油层进行溶解气驱采油期间,我们用地震法检测并解释了储层随时间变化情况,研究了其可行性。这次研究综合了油藏工程的流量模拟、岩层物性量值和变换值、叠前地震模拟及北海油藏实际模型的偏移等。该油气采收监控分析法包括: ·综合了Norsk Hydro提出的油藏流量模拟结果(孔隙压力、温度和油、气及水的饱和度); ·综合应用了由岩芯资料测得和有关岩石物性方面的油藏地质信息(孔隙度、干弹性常数和密度); ·利用Gassmann公式计算油藏中纵波和横波波速的空间分布,以及采油的流量模拟结果; ·利用克希霍夫弹性模拟算法在采油期间模拟多偏移距地面地震监控测量结果; ·利用叠前地震成象绘出作为油藏产油时间函数的地震响应差异图。根据流量模拟数据计算了油藏岩石物性的空间分布,并在三个采油时间段:未采油前(基础测量)、采油56天之后(监控器1)及在采油113天之后(监控器2)绘出了有关的地震响应。对三个采油时期均做了多偏移距地震测量模拟。由于利用了实际地震采集参数,所以我们能在油藏采油过程流量模拟期间成功地检测和监控动态气顶膨胀。在实际地震噪声水平和频率带宽情况下,叠前偏移差异剖面上可清楚地看到气锥的证据。
During a dissolved gas flooding recovery of a reservoir in a horizontal well in the North Sea, we used seismic methods to measure and interpret reservoir evolution over time and studied its feasibility. This study combines the flow simulation of reservoir engineering, the magnitude and transformation values of rock properties, the prestack seismic modeling and the offset of the actual model of the North Sea reservoir. The hydrocarbon recovery monitoring and analysis method includes: • Integrated reservoir flow simulation results (pore pressure, temperature and oil, gas and water saturation) proposed by Norsk Hydro; • Integrated data obtained from core data and related rock (Porosity, dry elastic constants and densities) in terms of physical properties; • Gassmann’s formula for calculating the spatial distribution of longitudinal and shear wave velocities in the reservoir and the results of flow simulation of production; • Using the Kirchhoff Elastic Simulation Algorithm Simulate multi-offset ground-based seismic monitoring measurements during oil production; • Map seismic response differences as a function of reservoir oil production time using pre-stack seismic imaging. The spatial distribution of petrophysical properties of the reservoir was calculated based on the flow simulation data and analyzed in three production intervals: before oil recovery (basic measurement), after 56 days (monitor 1) and after 113 days (monitor 2) The relevant seismic response is plotted. Multi-offset seismic measurements were simulated for all three production periods. Due to the use of actual seismic acquisition parameters, we were able to successfully detect and monitor dynamic apex expansion during oil recovery process flow simulation. The evidence of gas cones can be clearly seen on the differential profile of prestack migration at the actual seismic noise level and frequency bandwidth.