Unconventional Technology:The Difference Between Successful Application and Unsuccessful Application(North America and Overseas)

摘要

The past two decades have seen the development and expansion of an approach to wellbore completions that has resulted in unlocking significant reserves from previously disregarded resource,and has been responsible for the North American shale gas‘revolution’or‘evolution’(depending upon how you see it). However,this approach has faced significant complications to appropriate,successful and economic deployment,when attempts have been made to export this process overseas. This ground-breaking completion approach was achieved as a direct result of the combination of two well-known and widely applied industry technologies,from distinct disciplines:namely horizontal lateral drilling and propped hydraulic fracture stimulation.This simple combination is referred to by a number of different designations which are used to describe the process,but it is most commonly referred to simply as multi-stage horizontal well hydraulic fracturing. The North American success story has been primarily accomplished through the application of two distinct variants of this technique,split by fundamental approach to the stage sequencing:namely the Plug &Perf approach and the Open Hole Multi-Stage completion system(typically ball-activated fracture ports).The Open Hole Multi-Stage completion system has typically been applied selectively,with a bias towards clastic formations,whereas Plug&Perf has been more widely applied and almost exclusively dominates the shale completion environment. This paper will describe the engineering aspects of the multi-stage horizontal well hydraulic fracturing process,as well as those particular North America conditions and deliberate compromises that have been made,in order to encourage this approach to become established and develop further.Such analysis will include a holistic approach to the global market conditions,in order to better understand the local and regional factors that have played such a fundamental role in North American success,many of which have been erroneously overlooked elsewhere.This paper will investigate a number of these key issues and factors,particularly related to completion and reservoir interaction that should be considered carefully when choosing to export such techniques to new areas of application outside of North America.This will include an understanding of the key data that should be acquired,from the early exploration and subsequent appraisal wells,so that appropriate decisions can be made efficiently.