WELL COMPLETION AND STIMULATION BY BHARAT KUMAR HARANI ASSISTANT PROFESSOR DAWOOD UNIVERSITY OF ENGINEERING & TECHNOLOGY, KARACHI

Introduction to well completion General Procedure of well completion Open hole well completion Cased hole well completion

Informal definition: The high time of the well when engineer and personnel comes to decide whether to install the production casing in order to initiate the production at the surface or it should be abandoned. Technical Definition: Well completion means to prepare the well for production by installing the necessary equipments into the well in order to allow the safe and controlled flow of HCS at the surface.

 In an open hole well completion the production casing is just set above the pay zone, while the entire deepen bottom of pay zone is left uncased.

OPEN HOLE COMPLETION Advantage: Simple Saving in cost and time Disadvantage: No selective control Difficult to isolate water or gas Breakthrough Cross flow can not be controlled Not suitable for unstable Formation Application: Low cost/multi well developments Deep consolidated wells. Naturally Fractured reservoirs. Copyright 2007,, All rights reserved

For the most common type of well completion today involves the cased hole completion,in which the production casing and liner are cemented and perforated subsequently.

SINGLE COMPLETION WITH CEMENTED AND PERFORATED CASING Perforated Interval Production Casing Surface Casing Packer RESERVOIR Tubing Copyright 2007,, All rights reserved

COMPLETION WITH CEMENTED AND PERFORATED CASING Advantage: Selective production Zonal Isolation Water/Gas Shut-off Disadvantage: Extra cost (casing and cement, perforation) Formation Damage Application: Consolidated formation. Multi reservoirs with different pressures. When dual Completions are required Copyright 2007,, All rights reserved

A Liner is installed across the pay zone It can be divided into two: Screen Liner and perforated liner Screen Liner : Casing is set above the producing zone and an uncementedscreen and liner assembly isinstalled across the pay zone

OPEN HOLE GRAVEL PACK COMPLETION RESERVOIR TUBING PACKER LINER HANGER SLOTTED,PERFORATED OR SCREEN LINER SURFACE CASING PRODUCTION CASING GRAVEL PACK Copyright 2007,, All rights reserved

Casing is set above the producing zone and a liner assembly is installed across the pay zone and cemented in place. The liner is then perforated selectivelyfor production.

Production casing is cemented through the producing zone and pay section is selectively perforated

PRODUCTION TUBING IS PERFORATED AND CEMENTED

Casingflow: large flow rate no tubing is required, used in middle east. Tubing and Annulus flow: large flow rate flow segregation. Tubing flow: Used widely in Malaysia due to safety, may use one more tubing strings.

Simplest way of completing the well In this method well is completed by single zone with single tubing

In this multiple branches are drilled from a single zone It is used to improve productivity from closely spaced target zones.