JCPT Paper 4篇 [复制链接]

【文件名】 SAGD Operations in the Presence of Overlying Gas Cap and Water Layer¡ªEffect of Shale Layers
【文件格式】PDF
【页数】 12
【内容介绍】 The technical and commercial success of SAGD projects over the past decade has opened the door to the development of a
large number of bitumen reservoirs in Canada, previously thought uneconomical to produce. Some of these reservoirs have overlying gas caps and/or water zones. Some studies have suggested that gas-cap production might “sterilize” the underlying bitumen. Many such studies however, assumed rather thick continuous pays with high permeability, and considered an infinite gas-cap.
In this work, a simulation study was conducted to examine the feasibility of bitumen production from a certain project area in Alberta, using the SAGD process, and to study the effect of production from the gas cap. A decision needed to be made as to whether gas production should be delayed until after bitumen production. The large well spacing did not allow a detailed description of the connectivity of the shale layers. The uncertainty was compounded by the geological setting of the study area, a system of channel sands cut through the original marine sand and shale deposits. Since the actual shale connectivity and thickness was unknown, a methodology was developed to incorporate
different geological descriptions using the available core and log data. Five reservoir models were developed. Bitumen recovery, average oil production rate, and cumulative steam-oil ratio (SOR) obtained from thermal simulation were the three main parameters used for evaluation of the attractiveness of bitumen recovery operations. These numbers were compared with some of the corresponding values reported and/or forecast for economically feasible operations such as the UTF and Christina Lake projects. The effect of pressure reduction (caused
by gas-cap production) on production rate and SOR was also investigated.
The results indicated that for conditions considered in this study the effect of gas production on bitumen recovery was minor, and appeared as a small deceleration of the recovery and a small increase in SOR.
【附件个数】 1
【威望要求】 5

【文件名】 Dynamic Material Balance(Oil or Gasinplace without shutins)
【文件名】 Modelling of Convective Mixing in CO2 Storage
【文件名】 The False Lucre of Low-Pressure SAGD

【文件名】 The False Lucre of Low-Pressure SAGD
【文件格式】 PDF
【页数】 8
【内容介绍】 The recent trend in SAGD is towards low-pressure steam injection. The intention is to be more thermally efficient: steam at
lower pressures has a greater proportion of its heat as latent heat, which is the dominant source of heat released to the cold reservoir.
The oil sand then warms up to the steam temperature, thus mobilizing the bitumen. The SAGD process must be thermally efficient for optimal economic viability.
However, a more rigorous examination of the SAGD process presented here, inclusive of surface processes, reveals that there are fewer thermal benefits in operating at lower pressures. In addition, SAGD will be hindered by low-pressure injection due to higher viscosities and the inhibited dilation of the unconsolidated sandstone reservoir. This paper demonstrates that a complete analysis of the SAGD process favours operation at high pressures, and that SAGD at low pressures will be less effective.
【附件个数】 1
【威望要求】 5

【文件名】 Modelling of Convective Mixing in CO2 Storage
【文件格式】 PDF
【页数】 9
【内容介绍】 Accurate modelling of the fate of injected CO2 is necessary if geological storage is to be used at a large scale. In one form
of geological storage, CO2 is injected into an aquifer that has a sealing caprock, forming a CO2 cap beneath the caprock. The diffusion of CO2 into underlying formation waters increases the density of water near the top of the aquifer, bringing the system to a hydro-dynamically unstable state. Instabilities can arise from the combination of an unstable density profile and inherent perturbations within the system, e.g., formation heterogeneity. If created, this instability causes convective mixing and greatly accelerates the dissolution of CO2 into the aquifer. Accurate estimation of the rate of dissolution is important for risk assessments because the timescale for dissolution is the timescale over which the CO2 has a chance to leak through the caprock or any imperfectly sealed wells.
A new 2D numerical model which has been developed to study the diffusive and convective mixing in geological storage of CO2 is described. Effects of different formation parameters are investigated in this paper. Results reveal that there are two different timescales involved. The first timescale is the time to onset the instability and the second one is the time to achieve ultimate dissolution. Depending on system Rayleigh number and the formation heterogeneity, convective mixing can greatly accelerate the dissolution of CO2 in an aquifer. Two field scale problems were studied. In the first, based on the Nisku aquifer, more than 60% of the ultimate dissolution was achieved after 800 years, while
the computed timescale for dissolution in the same aquifer in the absence of convection was orders of magnitude larger. In the case of the Glauconitic sandstone aquifer, there was no convective instability. Results suggest that the presence and strength of convective instability should play an important role in choosing aquifers for CO2 storage.
【附件个数】 1
【威望要求】 5

【文件名】 Dynamic Material Balance(Oil or Gasinplace without shutins)
【文件格式】 PDF
【页数】 9
【内容介绍】 This paper is to be presented at the Petroleum Society’s 6 th Canadian International Petroleum Conference (56 th Annual Technical Meeting), Calgary, Alberta, Canada, June 7 – 9, 2005. Discussion of this paper is invited and may be presented at the meeting if filed in writing with the technical program chairman prior to the conclusion of the meeting. This paper and any discussion filed will be considered for publication in Petroleum Society journals. Publication rights are reserved. This is a preprint and subject to correction.
【附件个数】 1
【威望要求】 5