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...reuse Miscible injection is a proven, economically viable process that significantly increases oil recovery from many different types of reservoirs. Fieldwide projects have been implemented in fields around ...e projects being onshore North American fields. Many of these projects are quite mature, making the recovery and production-rate benefits well established. As a result, the ability to predict ...recovery levels, rate improvements, costs, and resulting economics can now be considered proven and reliable...
Miscible injection is a proven, economically viable process that significantly increases oil recovery from many different types of reservoirs. Fieldwide projects have been implemented in fields around the world, with most of these projects being onshore North American fields. Many of these projects are quite mature, making the recovery and production-rate benefits well established. As a result, the ability to predict recovery levels, rate improvements, costs, and resulting economics can now be considered proven and reliable. The purpose of this chapter is to introduce some fundamental concepts about miscible displacement, suggest some methods of predicting the benefits of miscible injection, and present a few field examples that demonstrate what has been accomplished with miscible injection. The schematics at the bottom of Figure 1.3 illustrate the pore-level recovery mechanisms discussed earlier (Figure 1.2). At the end of the waterflood, residual oil is a discontinuous phase that occupies approximately 40% of the pore space. Early in the miscible flood [3.0 to 3.5 total pore volumes (PV) injected], some of this oil has been miscibly displaced by solvent from the higher-permeability flow path (on the pore scale). However, some oil also has been initially bypassed by solvent. Note that this bypassing at the pore level is much different from solvent bypassing, which can occur at the field scale because of larger-scale reservoir heterogeneities. As depicted in the schematic corresponding to late in the flood (to 7.0 total PV injected), part of this locally bypassed oil is subsequently recovered by extraction and swelling that takes place as solvent continues to flow past the bypassed oil. In this case, approximately 30% of the total amount of oil recovered by the CO2 flood was recovered by extraction and swelling. After Jerauld (solid lines are the reference model, and dashed lines are the scaleup model). In field projects in which the displacement was above either the MMP or the MME, residual oil saturation determined by coring behind the solvent front varied from approximately 3 to 10% PV.
... plotted against mobility ratio, showing lines of a constant ER (1 – 0.72Sw) for a producing WOR of 5. Fig. 5 – Permeability variation plotted against mobility ratio, showing lines of a constant ER (1... of the dynamics of the water/oil-displacement process and the primary variables that influence the recovery efficiency. Use this section to list papers in OnePetro that a reader who wants to learn more shou...
This section discusses the impact of vertical variations in permeability and the effect of gravity on simple 2D reservoir situations in which the areal effects are ignored. Gravity effects always are present because for any potential waterflood project, oil always is less dense than water, even more so after the gas is included that is dissolved in the oil at reservoir conditions. The discussion below does not include the Pc effects on vertical saturation distributions. Through countercurrent imbibition, Pc effects help to counteract nonequilibrium water/oil saturation distributions. The mathematics of including Pc effects makes the problems too complicated for inclusion here.
...those illustrated in Fig. 5. Fig. 6 shows a less successful conversion to CHOPS. Fig. 2-CHOPS Well 5/4, Luseland field, Saskatchewan. Fig. 3-CHOPS Well 3/17, Luseland field, Saskatchewan. Fig. 4-CHOPS... to 50 m3/d (average of 21.6 m3/d/well in 1998) for an overall 4.9-fold increase. Expected per-well recovery went from 3 to 8% to 12 to 25% oil originally in place (OOIP). Although water production has inc...
Cold heavy oil production with sand (CHOPS) is a relatively recent technology. As such, only a few case histories of its application over a number of years have been published. Nonetheless, those that are available provide insight into the application of this technology. A detailed Luseland field case history has been published. It had a long history (12 to 15 years) of slow production with reciprocating pumps, an attempt to produce with horizontal wells (6 wells, all failures), and then a conversion to CHOPS through reperforation and progressing cavity (PC) pump installation.