Application of Moving Reference Point MRP Method to Cotton Valley and Travis Peak Sand Fracturing Treatments
Authors: Al-Husain H. M. , Soliman M. Y. , Stegent N. A. 
Published: January 2017

The main objective is to extend the Moving Reference Point (MRP) application to hydraulic fracturing treatments in the Cotton Valley and Travis Peak formations at east Texas. The ability to make corrective decisions to the pumping schedule, as the treatment is ongoing, is one of the advantages of this kind of analysis. An understanding of the treatment pressure-time trend as a diagnostic tool can significantly improve the efficiency of future hydraulic fracturing treatments and enhance field development optimization.

The MRP technique was developed by Pirayesh et al. (2013) as an improvement compared to the Nolte and Smith (1981) method, which identifies in progress fracture propagation behavior during pumping. Both works are based on the original power-law fracture propagation theory developed by Perkins and Kern (1961) and refined by Nordgren (1972). Unlike Nolte-Smith, the MRP technique uses Cartesian-type plot and treatment pressure-time record, assumes that the fracture goes through cycles of dilation, fracture propagation, and height growth, and includes in its workflow a MRP that makes identification of the pressure change mode easy and more reliable.

The results show the viability of the MRP technique in five wells completed across the Cotton Valley and Travis Peak formations. The disadvantages in the Nolte-Smith method, in terms of closure pressure (Pc) requirement and log-log scale, are compensated for by the MRP method through using the treating pressure and a Cartesian-type plot. Unlike the net pressure (Pnet)-time log-log plot, the fracture behavior/mode can be easily visualized by the e-time Cartesian plot. As suggested by the MRP method, the results indicate that the fracture experiences alternating cycles of dilation, fracture extension, and height growth during the pumping period because of the formation complexity, rather than continuous fracture propagation as proposed by the Nolte-Smith model. The MRP reference point enables better handling of treating pressure fluctuation and simplifies pressure change mode identification. Difficulties relating the fractures’ physical description to the formation geology were encountered because of the unavailability of the wells’ completion and petrophysical information. Subsequently, the results revealed the formation complexity, and observations and recommendations were made to optimize future fracture designs, mainly through early sanding out detection, fluid efficiency recognition, and larger treatment suggestions, and showing the geological parameter's impact on the fracture behavior.

This paper is focused on the future fracture design improvement and what if the MRP was used while pumping. It shows the advantages of using such a technique as a reliable pressure-time diagnostic tool. The previous publications about the MRP discussed mainly the methodology and the fracture mode physical description. This paper offers suggestions to ultimately enhance the Cotton Valley and Travis Peak formations development and helps operators to make proper decisions on the fly during fracture treatments.