Which model is part of influx?
Several models have been proposed for quantifying the influx of water accumulated into the reservoir. Among the classic models, the most used are van Everdingen & Hurst, (1949), Hurst modified (1958), Fetkovich approximate (1971), Carter & Tracy (1960), Allard & Chen (1984), and Leung (1986).
What is aquifer influx?
Aquifer water influx is an important mechanism which effects the performance of natural gas reservoirs. The influx of water has serious consequences in the estimation of gas reserves through material balance and in the prediction of future pressures.
What is water influx?
1. n. [Well Testing] The replacement of produced fluids by formation water. Most petroleum reservoirs are underlain by water, and water influx into a reservoir almost always takes place at some rate when gas or oil is produced.
What is an infinite aquifer?
[′in·fə·nət ′ak·wə·fər] (hydrology) The portion of a formation that contains water, and for which the exterior boundary is at an effectively infinite distance from the oil reservoir.
What causes water influx?
As pressure depletion proceeds, the pressure difference between the reservoir and aquifer grows rapidly and then abates as the aquifer and reservoir eventually equilibrate. This pressure interaction causes the water influx rate to start at zero, grow steadily, reach a maximum, and then dissipate.
What are the layers of an aquifer?
There are two general types of aquifers: confined and unconfined. Confined aquifers have a layer of impenetrable rock or clay above them, while unconfined aquifers lie below a permeable layer of soil.
What is Waterdriver mechanism?
1. n. [Well Completions] A reservoir-drive mechanism whereby the oil is driven through the reservoir by an active aquifer. As the reservoir depletes, the water moving in from the aquifer below displaces the oil until the aquifer energy is expended or the well eventually produces too much water to be viable.
What is an aquifer model?
A groundwater flow model is a mathematical representation of groundwater flow through an aquifer, which is composed of saturated sediment and rock.
What is an artesian flow?
artesian well, well from which water flows under natural pressure without pumping. It is dug or drilled wherever a gently dipping, permeable rock layer (such as sandstone) receives water along its outcrop at a level higher than the level of the surface of the ground at the well site.
How do you tell if an aquifer is confined or unconfined?
A Confined Aquifer is found deep beneath the ground level, while an unconfined aquifer is found just below the ground level.
What is aquifer strength?
The aquifer strength also refers to how well the aquifer mitigates the reservoir’s normal pressure decline. A strong aquifer refers to one in which the water-influx rate approaches the reservoir’s fluid withdrawal rate at reservoir conditions.
What is water encroachment?
Encroachment increases impervious cover adjacent to lakes, rivers and wetlands, thereby increasing the rate and volume of runoff, loading of sediment and other pollutants, and temperature of the receiving water.
What is a water influx model?
Water influx models are mathematical models that simulate and predict aquifer performance. Most importantly, they predict the cumulative water influx history. When successfully integrated with a reservoir simulator, the net result is a model that effectively simulates performance of water drive reservoirs .
How important is the water influx from adjacent aquifers in reservoir management?
Among the several sources of uncertainty in reservoir management, calculation of the water influx from adjacent aquifers is undoubtedly one of the most important. Several models have been proposed for quantifying the influx of water accumulated into the reservoir.
Is there a linear aquifer model for an Edgewater Drive?
Fig. 2 – Linear aquifer model for (a) an edgewater drive and (b) a bottomwater drive. van Everdingen and Hurst solved the applicable differential equations analytically to determine the water influx history for the case of a constant pressure differential at the aquifer/reservoir boundary.
What is the dimensionless water influx of an aquifer?
The dimensionless water influx, WD, is a function of tD and reD and depends on whether the aquifer is infinite acting or finite. The aquifer is infinite acting if re approaches infinity or if the pressure disturbance within the aquifer never reaches the aquifer’s external boundary.