Abstract
Abstract
Coal Bed Methane (CBM) development in India has emerged as one of the cleanest solutions to the fuel energy requirements of this energy-starved country. Favorable market scenarios and lucrative gas prices are enabling operators in this business to target aggressive well-completion schedules. This study discusses the techno-economic benefits realized by the operator company of using combined coiled tubing (CT) deployed hydrajetting and fracturing services instead of conventional wireline perforations in CBM wells.
The service company introduced a unique fracturing service that integrates six processes – depth correlation with CT, hydra-jet perforation, hydra-jet fracture initiation, hydraulic fracture stimulation, zonal isolation using a sand plug, and wellbore cleanout using CT. It completes these processes in one single trip-in-hole, making the service cost and time efficient and eliminating the use of wireline for perforating and setting bridge plugs in the well which requires multi-stage fracturing. The technology in use, lessons learned, and knowledge gained from operations in India are shared in this paper.
The process employs a customized CT bottom-hole assembly (BHA) at the core of its service. Customized engineering solutions for hydrajetting can be developed based on casing specifications, cementing conditions, and stimulation design. The principle of hydrajetting perforations and the BHA details are discussed along with its benefits over the alternative techniques. The experience gained during operations allowed the service company to optimize jetting flow rates, differential pressures, and back pressures to improve its operational efficiency and also allow maximum proppant to be placed into the formation being stimulated. Implementing the lessons learned increased the hydrajetting tool life from 25-30 sets of perforation to about 40 per tool. The paper also discusses job design improvements implemented to prevent sanding up the wellbore leading to stuck CT. Finally, the paper discusses the economic benefits achieved by the operator company leading to increased productive time and a faster rate of well completion.
CBM fields require excessive dewatering before they break out gas and become commercially viable projects. The technology discussed in this paper enables the operators to put the maximum number of wells on production, in a shorter period maximizing the Net Present Value (NPV) of the asset.