Shale Gas Novel Technology: Is Coiled Tubing Undulating Completion Compatible in Substituting Multistage Hydraulic Fracturing in Shale Gas Production?

Abstract

The most common technique of shale gas production is massive or multistage hydraulic fracturing. However, as massive multistage fracturing involves relatively higher capital and is of a negative impact to environment, this paper will discuss the application of undulating coiled tubing as a potential substitute for conventional multistage fracturing in shale production - of which is more economical and has proven to be effective in the production of conventional hydrocarbon from thin and low permeability reservoir. This study utilizes reservoir data extracted from publicly available Haynesville Shale data. Haynesville is an organic-rich shale play which extends across northeast Texas and northwest Louisiana, US. Overlain by Bossier shale, Haynesville is a unique shale play compared to other plays in US as it is relatively deep; with true vertical depth (TVD) within the range of 11,000 to 14,500 ft, abnormally high-pressure gradient (0.72 to 0.91 psi/ft), and temperatures greater than 300 °F (Thompson, et al., 2011). Haynesville will be the target shale play in this study that will be assessed by production simulation using both massive hydraulic fracturing and undulated well completion. Each production method will then be assessed economically. This paper shows the applicability of undulated well completion to substitute massive hydraulic fracturing in producing hydrocarbon from shale plays, in terms of technical deliverability as well as economic viability for final warranty of the profitability of the technique. Production performance of undulated well is comparable to that of hydraulically fractured well. Also, the application of undulating drilling proves to have significantly less negative impact on the environment – of which has been the major concern of multistage fracturing due to its pumping at high pressures and huge amount of water needed. Ultimately from economic perspective, the production of shale gas using undulating coiled tubing drilling is attractive as it requires less capital investment. Undulated wells do not require high-pressure pumped water which makes the completion more environmentally friendly than hydraulic fracturing. The unprecedented shale production using undulating coiled tubing drilling will also be the main discussion to be further compared with the widely and commonly used multistage fracturing. Moreover, between multistage fracturing and undulating completion, both technical and economic comprehensive assessments are conducted to see the well deliverability and profitability in shale gas production before subsequent decision to determine more profitable method.