Abstract

A variety of Saskatchewan medium and heavy crude atmospheric residues were tested in a batch reactor apparatus (autoclave) to determine their response to typical hydroprocessing conditions. The objective of the experimental program was to establish an understanding of the processing characteristics of Saskatchewan heavy crudes. Another aim was to determine If the production technique employed to recover the oil modified the processing characteristics. Heavy and medium crudes (including EOR and primary production) From the Southwest and Lloydminster producing areas were tested.

The batch experiments Indicated that a medium crude from a mature in-situ combustion enhanced all recovery (EOR) project resulted in the greatest coke formation. A heavy crude produced by a steam stimulation technique proved difficult to upgrade. Based an these experimental results the crudes were ranked to provide a comparison of the process1ng characteristics.

Introduction

Saskatchewan produces a variety of crude oils from the four main oil produc1ng areas 1n the province. The southeast (Weyburn-Estevan) crudes are light (>30 °API) and medium (20–30 °API) with high wax and medium sulphur contents. The southwest (Swift Current) crudes are medium gravity With high wax and sulphur content. The Kindersley-Coieville crudes are either light, waxy and low in sulphur or heavy with a high sulphur, nitrogen and asphaltene content. The Lloydminster crude is heavy, has a high sulphur, nitrogen and asphaltene content.

Saskatchewan's oil producing future rests in the development of the heavy oil resources in the Lloydminster area. The southeast and southwest areas are nearing their maximum economic recovery. Same potential exists with enhanced oil recovery methods for the southeast and southwest areas but because of the magnitude of the Lloydminster potential resource most oil development will occur in the Lloydminster area within the next decade.

Heavy oil recovery by primary and secondary (waterflooding) methods result In a 3–10% recovery of the oil-in-place. To develop Saskatchewan's resource, EOR methods are seen as a necessity. EOR techn1ques currently being developed by the industry are known to change the characteristics of the produced oil. Some changes improve the quality, however, mast changes will require a downstream refiner/ upgrader to adjust the operation to suit the feedstock and desired product slate. If the characteristic changes are significant enough the refiner may seek alternative feedstock sources.

This paper is based on the results from a research project Funded by the Canada-Saskatchewan Fossil Fuels Agreement to establish a database of the processing characteristics of Saskatchewan crude oils. The project concentrated on med1um and heavy crudes From the western producing areas of the province. These areas were selected because of the previously mentioned resource potential and also the existence and maturity of the EOR pilot projects. Another reason For this selection is that the two planned upgraders will draw their Feedstock from these areas while the crude production From the southeast will continue to be exported out of the province.

APPARATUS

A high pressure, high temperature batch reactor, along with some associated equipment (temperature controllers, a wet test meter and a microcomputer for data acquisition), was assembled for the project (Figure 1).

This content is only available via PDF.
You can access this article if you purchase or spend a download.