Abstract

This paper describes a method, that is presently in use, which helps maintain control of a pattern type waterflood and requires a minimum of supervision. The control is accomplished by using the computer to automatically schedule production andinjection on a monthly basis having taken into account previous months' production and injection volumes. The program also calculates the monthly and cumulative voidage status of each pattern.

A minimum of supervision has been achieved through the use of seven brief information reports which present all the pertinent data required to supervise the flood.

The program produces the monthly operations report for distribution to the Unit partners and a considerable amount of organized data necessary to study the effectiveness of the flood and to allow a more accurate prediction of future equipment requirements.

Introduction

This paper describes a method of scheduling, monitoring, and optimizing the performance of pattern waterflood projects. The system is presently in operation handling some 900 producing wells and 300 injection wells in the propertiesoperated by Mobil Oil Canada, Ltd. in the Pembina field, Alberta. These properties cover an area of approximately four townships and some 600 000 barrels of oil are produced each month.

Due to the quantity of data handled, together with the innumerable, repetitive calculations, it was decided that the scheduling of the field production and injectioncould be most effectively accomplished with the use of the computer.

The following benefits are being realized from the use of this system:

  1. The oil to be produced and the quantity of water to be injected each month are presented, several days before the beginning of each month, to the field operating personnel allowing them the opportunity to plan their work in advance.

  2. A complete summary of the previous months' net withdrawals are made available on an individual well, pattern and project basis.

  3. Any deviations from the previous months' planned production and injection schedules are automatically corrected in subsequent months. In cases where these deviatians are large a special repart brings these anomalies to the attention of the appropriate people.

  4. Six other reports are produced by the computer presenting performance data required by supervisory and engineering staffs. These reports present the pertinent data required for internal control and planning, the regulatory bodies and the joint interest owners.

Mobil Oil has been using a computer to program and monitor the production and injection of the Pembina pattern floods since 1960. The programs have been modified from time to time and have been completely rewritten twice. The present program is by far the most sophisticates and most successful yet devised and is the fruit of six years of experience with this problem.

DISCUSSION
Basic Concepts Used in the Product ion of a Pattern Waterflood

This paper discusses the operation and control of inverted five and nine-spot waterflood patterns (Figure J), however, the principles involved are applicable to all pattern configurations.

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