Reservoir Engineering Techniques Used To Predict Blowout Control During the Bay Marchand Fire
Authors: Miller Robert T. , Clements Ronald L. 
Published: December 2007

Documented here in part are the reservoir engineering techniques used during the Bay Marchand fire. Before any plans for the kill operations were made, a brief reservoir simulation study was conducted to gain insight into the mechanics of fluid flow. Some of the predictions made with the model are compared with actual field results.

Introduction

A fire broke out on Shells Oil Co.'s Platform "B" at Bay Marchand Offshore Louisiana on Dec. 1, 1970. Of the 22 completed wells (43 zone completions) and two drilling wells, 11 caught fire; and Shell immediately set up an emergency task force to handle the problem of extinguishing the fire and capping the wells. This paper is one of a series that documents the activities of that task force during the 136 days required to cap all of the wells on the platform.

Questions To Be Answered

The reservoir engineering section of the task force was rapidly deluged with questions, all pertinent and important, for which other engineering sections and management needed answers before they could adequately plan and conduct the kill operations. These plan and conduct the kill operations. These inquiries can be summarized into four basic questions that had to be answered for each of the 11 wells to be capped.

(1) What is the possibility that circulation will belost if a relief well were to penetrate a blowoutzone within a 25-ft radius of the producing well?

(2) What surface injection pressure can be anticipatedduring a high-injection-rate kill operation?

(3) How much water must be pumped into the reliefwell before water breaks through in theproducing well.

(4) How much water must be pumped into the reliefwell to achieve 100 percent water production inthe producing well?

Techniques Employed

Question 1 was easily answered; however, we were not able to come up immediately with simple answers to the remaining questions nor rapid methods of dealing with the problems. Intuition and experience with conventional fluid injection projects strongly suggested that the predominant flow pattern from the injector would be radial, but there was some uncertainty as to the effect of the producing well on this pattern, both before and after water breakthrough. Accordingly, we decided to conduct a relatively brief reservoir simulation study, having a very specific and limited objective: to gain insight into the mechanism involved in controlling a blowout by water injection from an adjacent well.

The Reservoir Simulation Study

All simulations of a blowout kill operation were made in a two-dimensional areal mode utilizing COMSIMa three-phase, three-dimensional, compressible simulator developed by Shell Development Co. The investigation and its results were all subject to the following assumptions and restrictions:

(1) The reservoir was assumed to be horizontal, homogeneous, and isotropic.

(2) Interference effects from other wells orreservoir boundaries were ignored.

(3) Gravity and capillary effects were neglected.

(4) Only the injection of water was simulated.

JPT

P. 234