为了在油砂蒸汽辅助重力泄油开发过程中,根据不同时刻井筒沿程蒸汽腔发育状况实时调整注采温度差（Subcool）,以防止蒸汽突破并提高热量利用效率,开展了汽液界面智能调控模型比例-积分-微分（PID）控制方程的系数优选研究。以蒸汽腔内液池为研究对象、Subcool为调控目标,依据热量守恒和物质平衡原理建立了PID控制方程系数优选数学模型,采用该模型和Ziegler-Nichols（Z-N）整定法优选了适用于加拿大M区块的汽液界面智能调控模型,并通过数值模拟评价了应用效果。研究结果表明：当采用比例、积分和微分系数组合时,进一步缩短了注采温度差达到Subcool目标值的时间,提高收敛速度和健壮性。与常规注汽相比,模型优选方法下智能注汽显著改善了井筒沿程蒸汽腔均匀扩展程度,提高产油量的同时降低了汽油比,模拟结果与Z-N整定法相似,但模型优选法简化了智能调控模型的优选过程,更为方便快捷。图9参18
梁光跃
,
刘尚奇
,
沈平平
,
刘洋
,
罗艳艳
. 油砂蒸汽辅助重力泄油汽液界面智能调控模型优选[J]. 石油勘探与开发, 2016
, 43(2)
: 275
-280
.
DOI: 10.11698/PED.2016.02.14
In order to prevent steam breakthrough and improve thermal efficiency in the process of SAGD development of oil sands by real-time adjustment on injection-production temperature difference (Subcool) according to the growth situations of steam chamber along the wellbore, a series of studies were conducted on coefficients optimization of proportional-integral-derivative (PID) control equation for the steam-liquid level intelligent control model. According to heat conservation and material balance principles, a mathematical model for determining the coefficients of PID control equation was established with the liquid pool in the steam chamber as the objective and the Subcool as the control target. The intelligent steam-liquid level control model suitable for M Block in Canada was optimized using this mathematical model, together with the Ziegler-Nichols (Z-N) tuning method. Application effects of these PID control strategies were evaluated by reservoir numerical simulation. The results show, when the combination of PID proportional, integral and derivative coefficients are used, the time scale for Subcool to evolve to the set point is minimized and the convergence speed and robustness are improved. Compared with conventional steam injection process, the intelligent steam injection based on the PID coefficient optimization method is much better in the uniform conformance of steam chambers along the wellbore, higher in oil production and lower in steam-oil ratio (SOR). Both the model optimization method and the Ziegler-Nichols tuning method are similar in simulation results. Based on the former method, however, the optimization process of the intelligent control model is simplified greatly, so it can be implemented more conveniently and rapidly.
[1] 穆龙新. 重油和油砂开发技术新进展[M]. 北京: 石油工业出版社, 2012.
MU Longxin. New progress of heavy oil and oil sands development technology[M]. Beijing: Petroleum Industry Press, 2012.
[2] 沈德煌, 吴永彬, 梁淑贤, 等. 注蒸汽热力采油泡沫剂的热稳定性[J]. 石油勘探与开发, 2015, 42(5): 652-655.
SHEN Dehuang, WU Yongbin, LIANG Shuxian, et al. Thermal stability of foam during steam drive[J]. Petroleum Exploration and Development, 2015, 42(5): 652-655
[3] EDMUNDS N R. Investigation of SAGD steam trap control in two and three dimensions[R]. SPE 50413, 1998.
[4] GATES I D, LESKIW C. Impact of steam trap control on performance of steam-assisted gravity drainage[R]. Calgary, Alberta: Petroleum Society’s 59th Annual Technical Meeting, 2008.
[5] BANERJEE S, JOBLING R, ABDELFATTAH T, et al. The role of autonomous flow control in SAGD well design[R]. SPE 166266, 2013.
[6] ZENGQ S, WANG Z M, WANG X Q, et al. A novel autonomous inflow control device design based on the combination of two dynamic fluid technologies[R]. SPE 170069, 2014.
[7] OYEKA O, FELTEN F, LEAST B. Screen-inflow-design considerations with inflow control devices in heavy oil[R]. SPE 170097, 2014.
[8] SHAD S, ENG P, YAZDI M M. Wellbore modeling and design of nozzle-based inflow control device (ICD) for SAGD wells[R]. SPE 170145, 2014.
[9] STAHL R M, SMITH J D, HOBBS S, et al. Application of intelligent well technology to a SAGD producer: Firebag field trail[R]. SPE 170153, 2014.
[10] CLARK H P, ASCANIAO F A, KRUIJSDIJK C V, et al. Method to improve thermal EOR performance using intelligent well technology: Orion SAGD field trial[R]. SPE 137133, 2010.
[11] BEDRY M, SHAW J. Using a new intelligent well technology completions strategy to increase thermal EOR recoveries: SAGD field trial[R]. SPE 154760, 2012.
[12] GATES I D, GOTAWALA D R. SAGD subcool control with smart injection wells[R]. SPE 122014, 2009.
[13] GOTAWALA D R, GATES I D. A basis for automated control of steam trap subcool in SAGD[R]. SPE 159170, 2012.
[14] STONE T, BROWN G, GUYAGULER B, et al. Practical control of SAGD wells with dual-tubing strings[R]. SPE 149352, 2011.
[15] STONET, DAMAS C E P, WOICESHYN G, et al. Advanced wellbore simulation of flow control devices with feedback control for thermal operations[R]. SPE 163594, 2013.
[16] STONE T W, LAW D H S, BAILEY W J. Control of reservoir heterogeneity in SAGD bitumen processes[R]. SPE 165388, 2013.
[17] ÅSTROM K, HAGGLUND T. PID controllers: Theory, design, and tuning[M]. USA: Instrument Society of America, 1995.
[18] IRANI M, GHANNADI S. Understanding the heat-transfer mechanism in the steam-assisted gravity-drainage (SAGD) process and comparing the conduction and convection flux in bitumen reservoirs[R]. SPE 163079, 2012.
