Page 220 - Introduction to Petroleum Engineering

ONSHORE FACILITIES 207

Storage tanks
Separator

Pump

FIgURE 11.2 Oilfield production equipment.

from the field. A tank battery is a collection of storage tanks at a field. Gas from the
separator is usually routed to a flowline or compressor. The compressor boosts the
pressure of the gas so that it can be injected into a flowline.
A central processing unit, or gathering center, is a location for collecting fluids
from multiple wells. The fluids produced from all connected wells flow through
gathering center separator(s) and into commingled storage tanks. The gathering
center can save money on processing fluids, but it can reduce the operator’s ability to
analyze production from each individual well.
Surface facilities such as drilling rigs, storage tanks, and compressor stations are
needed to drill, complete, and operate wells. The surface area required for installing
all of the facilities needed to develop a resource is called the footprint. The size of the
footprint has an impact on project economics and environmental impact. As a rule, it
is desirable to minimize the size of the footprint.
Drilling rigs may be moved from one location to another on trucks, ships, or off-
shore platforms; or drilling rigs may be permanently installed at specified locations.
The facilities may be located in desert climates in the Middle East, stormy offshore
environments in the North Sea, arctic climates in Alaska and Siberia, and deepwater
environments in the Gulf of Mexico and off the coast of West Africa.

Example 11.1 Pipeline Capacity
A. A gathering center receives oil from 16 wells. Each well can produce up
to 5000 bbl liquid per day per well. Maximum liquid flow rate is the flow
rate when all wells are producing at capacity. What is the maximum liquid
flow rate?
B. The pipeline from the gathering center to a processing facility can carry
50 000 bbl liquid per day. Can all of the wells produce at maximum liquid
flow capacity?