A Stepwise Approach to Lease Automation
Authors: Morgen R.A. , Dozier H.S. 
Published: December 2007

Automating of oil production leases may be approached in a step-by-step manner if proper planning is done initially. This paper summarizes the various automated processes in lease production, showing the limits and planning required. A hypothetical lease is studied and the equipment required to automate at each stage is set out.

Introduction

In order to proceed toward the objective of this discussion, "lease automation" is defined as the interconnection of several automatic or semi-automatic processes into a comprehensive over-all system to improve the efficiency of lease operation.

It is the writers' opinion, and also that of many but certainly not all system designers, that in lease automation each process should operate completely and independently within itself except for its interaction on other processes in the over-all system. This basic philosophy is essential to effecting a stepwise approach to lease automation and will apply throughout this discussion.

Technology has progressed to a degree that all processing on a lease can be integrated into a lease automation system. It is the purpose of this paper to discuss these lease processes, which concern fluid handling, and how each can be automated in a stepwise fashion.

Lease Processes

The fluid-handling processes from the wellhead to the pipeline consist basically of the following:well flow control,fluid routing,fluid processing,delivery to pipeline anddata gathering.

Note that the processes, as defined, do not require duplicating operations; instead, each is set out to obtain a desired end result. Around the philosophy that each process be self-controlled, it is possible to approach lease automation in a stepwise manner. A further examination of each process just defined will locate the functions that must be performed.

Well Flow Control

Well flow control can be defined as the supervision of the productivity of a well and may be done for a variety of reasons. Two of these might be: "on-off" or "intermitting" control to prevent a well from "pumping off" or to produce efficiently according to the particular well's characteristics; and "flow programming" for electrical load balancing or for proration reasons. These and other methods have been used on an automatic or semiautomatic basis for a number of years. As such, well flow control can be said to be a well established unit operation. However, these operations usually are on a per-well basis; that is, the programming clock is located at the wellhead or pumping unit. A central programming system for a number of wells offers several advantages. Two of these are: the well programs are more easily changed and synchronized, and the status of each well is more easily determined.

Fluid Routing

In this category are grouped well testing and the subsequent return of fluids to the proper points within the system to allow most efficient processing and proper accounting.

Well testing encompasses, first, the routing of the fluid to the proper test apparatus; second, the measurement of quantity and quality; third, and finally, the accumulation of the test data. Data may be accumulated in many ways, a few of which follow:local readout counters,strip-chart recorders (operational and analog),local printing or punch equipment andelectrically stored for later transmission to a central location.

Note that these forms are listed pretty much in the order in which they have been applied to lease automation. Also, note that they progressively require less operator attention.

At the conclusion of these operations, the fluids must be properly routed to a particular process. From a control standpoint, this single factor varies more than any other from lease to lease.

As an example, where one company's production is used it is usually necessary, when testing a well, to subtract the oil used by that company's pumps from the total oil measured during the test. It is also required to return oil to the company's "power oil tank" in order for the process to continue.

Another problem commonly encountered is the separation of "wet" and "dry" wells in order that the fluids from each get the best processing attention. Accounting requirements may also dictate the method by which fluids are handled.

Economically, it is desired to use only one test system regardless of special processing requirements.

JPT

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