State of the Art Biodegradable Diversion Technology Applied on Tight Carbonates Reservoir Leads to Maximized Production

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Authors

David Gonzalez (Weatherford) | Joel Ulloa (Weatherford) | Reza Safari (Weatherford) | Aws Al-Rawi (Weatherford) | Andrew Babey (Weatherford)

Publisher

SPE - Society of Petroleum Engineers

Publication Date

November 13, 2017

Source

Abu Dhabi International Petroleum Exhibition & Conference, 13-16 November , Abu Dhabi, UAE

Paper ID

SPE-188632-MS

Abstract

The need for diversion in acid stimulation jobs has become a necessity with which we cannot dispense. Various diverting agents are available commercially and can be used effectively when there is a low to moderate permeability contrast as well as porosity. If there are long intervals with high permeability intermixed, mechanical diverter would almost be considered as the sole solution especially when zonal isolation by the means of specialized tools is not required.

This work is aimed at the outcome from using a solid particulate diverter which is a biodegradable particulate diverter that maintains its diversion effect for as long as needed. By controlling certain factors, the diversion time can be increased or decreased. The diversion technique was first introduced to the Middle East in December 2016 to assist in finding a solution for the high permeable intervals that exist in Iraqi wells. The wells need to be matrix acidized and post stimulation PLTs show that production is coming from the high permeable intervals whilst other intervals that have lower permeability, showing no or low production because of the uneven treatment of the zone.

Lab tests were conducted to formulate a suitable carrier fluid that would possess optimum viscosity helping transport the solid particulate diverter system to the intended area. Along with, a suitable breaker fluid that would cleanly break the carrier fluid at the end of the treatment to assure efficient flow back is tested. Temperature and pH were maintained to simulate downhole conditions and achieve the most accurate results.

The job was successfully designed, prepared and performed. Real time optimization was conducted during the job which resulted in a more efficient operation.

The first observed post stimulation results was an increase of 5 m3 per hour. Two days following the stimulation, the records showed an increase in the production rate by approximately 25%.