Azeotropic Heated Vapour Extraction- A New Thermal-Solvent Assisted Gravity Drainage Recovery Process

Author(s):  
Rahman Khaledi ◽  
Hamed Reza Motahhari ◽  
Thomas J. Boone ◽  
Chen Fang ◽  
Adam S. Coutee
SPE Journal ◽  
2012 ◽  
Vol 17 (03) ◽  
pp. 680-686 ◽  
Author(s):  
Dharmeshkumar R. Gotawala ◽  
Ian D. Gates

Summary Full steam conformance along the well pair of the steam-assisted gravity-drainage (SAGD) oil-sands-recovery process is essential for high thermal efficiency. Conformance can be improved by controlling injection and production strategies to ensure that steam is delivered to target regions in the reservoir. Smart wells use interval-control valves (ICVs) that, conceptually, can be dynamically controlled to yield uniform steam injectivity along the well pair. Dynamic control algorithms, such as proportional-integral-derivative (PID) control and their associated controller parameters, have not yet been developed for the SAGD processes that use ICVs. One control strategy would be to control the interwell subcool temperature difference—that is, the difference between the steam-injection temperature and the produced-fluids temperature. If this temperature difference is small, then the liquid pool above the production well is small and there is a likelihood of live steam production from the chamber. On the other hand, if the difference is large, the pool may rise above the injection well and gravity drainage is hindered because the chamber is largely filled with liquid. Here, the focus is on developing a simple, approximate theory for the behavior of the liquid pool at the base of the steam chamber to determine the ranges of values of control parameters to achieve a targeted interwell subcool temperature difference.


SPE Journal ◽  
2018 ◽  
Vol 24 (02) ◽  
pp. 477-491 ◽  
Author(s):  
Enrique Gallardo ◽  
Clayton V. Deutsch

Summary Steam-assisted gravity drainage (SAGD) is a thermal-recovery process to produce bitumen from oil sands. In this technology, steam injected in the reservoir creates a constantly evolving steam chamber while heated bitumen drains to a production well. Understanding the geometry and the rate of growth of the steam chamber is necessary to manage an economically successful SAGD project. This work introduces an approximate physics-discrete simulator (APDS) to model the steam-chamber evolution. The algorithm is formulated and implemented using graph theory, simplified porous-media flow equations, heat-transfer concepts, and ideas from discrete simulation. The APDS predicts the steam-chamber evolution in heterogeneous reservoirs and is computationally efficient enough to be applied over multiple geostatistical realizations to support decisions in the presence of geological uncertainty. The APDS is expected to be useful for selecting well-pair locations and operational strategies, 4D-seismic integration in SAGD-reservoir characterization, and caprock-integrity assessment.


MethodsX ◽  
2021 ◽  
Vol 8 ◽  
pp. 101531
Author(s):  
Shengfei Zhang ◽  
Hongzhuang Wang ◽  
Xinge Sun ◽  
Aiping Zheng ◽  
Zhongyi Zhang ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1743
Author(s):  
Bikash D. Saikia ◽  
Dandina N. Rao

The U.S. Deepwater Gulf of Mexico (DGOM) area that has some of the most prolific oil reservoirs is still awaiting the development of a viable enhanced oil recovery (EOR) process. Without it, DGOM will remain severely untapped. Exorbitant well costs, in excess of $200 million, preclude having extensive injection patterns, commonly used in EOR design frameworks. Aside from injection patterns, even operationally waterflooding has met with significant challenges because of injectivity issues in these over pressurized turbidities. The gas-assisted gravity drainage (GAGD) EOR process, that holds promise for deepwater environments because of lesser injectivity issues, among others, has been adapted in this work to overcome these limitations. A novel design in the form of a single well—gas assisted gravity drainage (SW-GAGD) process, has been demonstrated to emulate the benefits of a GAGD process in a cost-effective manner. Unlike conventional GAGD processes, which need multiple injectors and separate horizontal production wells, the SW-GAGD process just uses a single well for injection and well production. The performance of the process has been established using partially scaled visual glass models based on dimensional analyses for scale up of the process. The recovery factor has been shown to be in the range of 65–80% in the immiscible mode alone, and the process is orders of magnitude faster than natural gravity drainage. A toe-to-heel configuration of the SW-GAGD process has also been tested and for the configuration to be immune from reservoir layering, the toe of the well should ideally end at the top of the payzone. Better sweep of the payzone and consequent high recovery factor of 80% OOIP was observed, if the heel part of the bottom lateral is located in a lower permeability zone.


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