Low-Tension Waterflood Pilot at the Salem Unit, Marion County, Illinois Part 2: Performance Evaluation

Abstract

This paper evaluates a field test of a low-tension tertiary flooding process using a petroleum sulfonate surfactant. Observation-well data process using a petroleum sulfonate surfactant. Observation-well data showed that with proper formation conditioning and sufficient surfactant the process effectively displaced all oil remaining after waterflood. Over-all production was 25 percent of expected, and various explanations for this performance are discussed. Introduction A regular 2-ha (5-acre), five-spot pilot test of a lowtension waterflood process was undertaken in a previously waterflooded Benoist sand in the Salem field, previously waterflooded Benoist sand in the Salem field, Marion County, 111. Part 1 of this paper presents the process and pilot descriptions, injection and production histories, and associated field operations. The objectives of this paper are to discuss parameters that may contribute to the process effectiveness and to evaluate the oil recovery performance. An accounting is made of flood components that were injected, produced, and retained in the formation. Both measured and predicted responses are reported. The use of tracers in predicted responses are reported. The use of tracers in allocating contributions from the four injectors to the producer and in detecting flow-path changes is described. producer and in detecting flow-path changes is described. Interpretation Techniques A computer model simulating tracer and chemical flooding in a stratified pattern was used to interpret pilot performance data. The reservoir was divided into five performance data. The reservoir was divided into five layers to represent the heterogeneity, and stream tubes were used to account for areal distribution of liquid. Within each layer and tube, flow was considered one dimensional, and crossflow between layers and tubes did no exist. The model incorporated the following features:Chemical transport accounting for dispersion, adsorption, and partitioning.Incompressible flow of aqueous and oil phases, with flow considered high-tension (immiscible) or low-tension (miscible-like) depending on the chemical environment.Non-Newtonian flow of polymer solution and permeability reduction because of polymer adsorption on the permeability reduction because of polymer adsorption on the rock. The following included in the pilot performance evaluation:Analysis of tracer data to verify quadrant flow patterns, fraction of production contributed by each patterns, fraction of production contributed by each quadrant, and vertical reservoir heterogeneity.The effect of the surrounding Benoist injectors and producers in conjunction with the adjacent aquifer. producers in conjunction with the adjacent aquifer.Estimation of chemical consumption based on tracer and chemical breakthrough volumes and concentration profiles at the observation and production wells.Comparison of simulated recovery performance with measured results. Flow Distribution Typical liquid distributions in vertically adjacent, high-and low-permeability flow intervals between one pilot injector and the producer are shown in Fig. 1. Also shown are the positions of the chemical banks at a given time. JPT P. 933

Surfactant Stabilized Oil-in-Water Nanoemulsion: Stability, Interfacial Tension, and Rheology Study for Enhanced Oil Recovery Application

“…Application of emulsion as an EOR agent has been reported in earlier studies . The low oil recoveries because of poor emulsion stability caused by the coalescence of droplets has limited its use. , Thus, the use of nanotechnology in emulsions can be a breakthrough in EOR, as it has the potential to revolutionize the current scenario of oil production from the matured oil fields . Nanotechnology, in general, refers to matters of atomic and molecular scale (nanometers), such as nanoemulsions .…”

The Effect of Dispersed Phase Salinity on Water-in-Oil Emulsion Flow Performance: A Micromodel Study

“…All of these unusual phenomena suggested severe challenges to oil recovery from water injection. Strange and Talash, Whiteley and Ware, and Widmyer et al have also reported poor oil recovery due to problems associated with the undesirable formation of stable macroemulsions in the oil fields. They observed formation of high-viscosity emulsions in the reservoir of homogeneous permeability, which required very high energy for flow in porous media.…”

Manvel Enhanced Recovery Pilot Design And Implementation

“…This period allowed sufficient time for well remedial work and to establish production and injection trends for the pilot. Polymer injection began in August 1977, andterminated in February 1978, For field testing an enhanced oil recovery process, it is important to maintain continuous operation. In a water drive reservoir such as exists at Manvel, 't is even more important to inject the surfactant and polymer solutions with a minimum of down Liae.…”