Safe, Pollution-Free Testing Of Offshore And Arctic Wells
Authors: Nutter B.P. , McGill H.L. , Scott B.J. , Fry H.D. 
Published: October 2008

Well testing offshore and in remote areas such as the Arctic incurs a substantial responsibility to provide complete test results with maximum safety and environmental protection. This paper describes the new developments in a rapidly advancing technology for testing in these high cost operations. Major emphasis is placed on producing good results to allow making correct decisions in these high investment wells. The subject matter reviews important aspects of both offshore and remote area well testing. Recent new developments included are surface instrumentation which monitors early downhole flow rate for better engineering of the test, safe provisions for wireline and coil tubing operations, testing with limited fluid production, and new downhole pressure actuated tools for high flow production type testing. Accessory equipment for wireline operations and future developments are also included.

INTRODUCTION

The continuing search for oil and gas, necessary for easing the worlds energy shortage, has led the petroleum industry to the more hostile environments such as deep sea operations of the Outer Continental Shelf and the remote frozen areas of the Arctic. When testing these wells during the drilling or initial completion stage, substantial emphasis must be placed on providing complete test results with maximum safety, protection of the environment, and at minimum rig costs.

The commercial value of the well must be clearly and accurately defined. If we consider development well costs such as drilling and production platforms, gathering and pipeline facilities it can clearly be seen that a complete and accurate evaluation of the reservoir during the initial testing can prevent a financial disaster. For this reason the well test must be complete in defining the properties of the reservoir fluid, the flow rate, the reservoir pressure, permeability, damage, extent of investigation, depletion, and reservoir anomalies. The initial testing should also determine the effectiveness of stimulation treatment in increasing production rate.

Many offshore testing operations can involve up to as many as 100 people on the rig and equipment costs exceeding the 50 million dollar range. For this reason it is of paramount importance that the well test be conducted with maximum safety of personnel and equipment.

Due to the close attention which is given to offshore and Arctic well operations by environmentalists, governmental agencies, and the fast and growing concern of the general public, the well testing operations must be pollution-free for maximum protection of the environment.

High rig costs exceeding $50,000 per day during offshore well testing operations, due to extra personnel, equipment, emergency standby facilities, etc. require maximum system reliability and minimum rig time consumption.

This paper summarizes and reviews those steps which have been taken by the energy companies, drilling contractors, and the service companies in an effort to achieve all of the above mentioned objectives in well testing operations.