The reservoir model developed in the previous two sections will now be applied to history-matching production data from a well in a volumetric, internal gas-drive reservoir. Actual oil production and instantaneous gas-oil ratios for the first 3 years of the life of the well are plotted in Fig. 12.1. The data for the problem were obtained… Continue reading The History Match
Incorporating a Flow Equation into the Model
The procedure mentioned in the previous section yields oil and gas production as a function of the average reservoir pressure, but it does not give any indication of the time required to produce the oil and gas. To calculate the time and rate at which the oil and gas are produced, a flow equation is… Continue reading Incorporating a Flow Equation into the Model
History Matching with the Zero-Dimensional Schilthuis Material Balance Equation
Development of the Model The equations do not have a time dimension associated with them. These equations simply relate average reservoir pressure to cumulative production. To obtain rate information, a method is needed whereby time can be related to either the average reservoir pressure or cumulative production. Single-phase flow in porous media was discussed and… Continue reading History Matching with the Zero-Dimensional Schilthuis Material Balance Equation
History Matching with Decline-Curve Analysis
Decline-curve analysis is a fairly straightforward method of predicting the future production of a well, using only the production history of that well. This type of analysis has a long tradition in the oil industry and remains one of the most common tools for forecasting oil and gas production.8–13 In general, there are two approaches to… Continue reading History Matching with Decline-Curve Analysis
Introduction
One of the most important job functions of the reservoir engineer is the prediction of future production rates from a given reservoir or specific well. Over the years, engineers have developed several methods to accomplish this task. The methods range from simple decline-curve analysis techniques to sophisticated multidimensional, multiflow reservoir simulators.1–7 Whether a simple or complex… Continue reading Introduction
Screening Criteria
Table 11.2 contains the screening criteria that have been compiled from the literature for the miscible, chemical, and thermal techniques. Table 11.2 Screening Criteria for Tertiary Oil Recovery Processes The miscible process requirements are characterized by a low-viscosity crude oil and a thin reservoir. A low-viscosity oil will usually contain enough of the intermediate-range components for the… Continue reading Screening Criteria
Screening Criteria for Tertiary Processes
A large number of variables are associated with a given oil reservoir—for instance, pressure and temperature, crude oil type and viscosity, and the nature of the rock matrix and connate water. Because of these variables, not every type of tertiary process can be applied to every reservoir. An initial screening procedure would quickly eliminate some… Continue reading Screening Criteria for Tertiary Processes
Problems in Applying Thermal Processes
The main technical problems associated with thermal techniques are poor sweep efficiencies, loss of heat energy to unproductive zones underground, and poor injectivity of steam or air. Poor sweep efficiencies are due to the density differences between the injected fluids and the reservoir crude oils. The lighter steam or air tends to rise to the… Continue reading Problems in Applying Thermal Processes
In Situ Combustion
Early attempts at in situ combustion involved what is referred to as the forward dry combustion process. The crude oil was ignited downhole, and then a stream of air or oxygen-enriched air was injected in the well where the combustion was originated. The flame front was then propagated through the reservoir. Large portions of heat… Continue reading In Situ Combustion
Steam-Drive Process
The steam-drive process is much like a conventional waterflood. Once a pattern arrangement is established, steam is injected into several injection wells while the oil is produced from other wells. This is different from the steam stimulation process, whereby the oil is produced from the same well into which the steam is injected. As the… Continue reading Steam-Drive Process