Delayed Oil Swell Packer for Openhole Zonal Isolation of Long Laterals Wells

Abstract

Swellable elastomer packers are the preferred choice for openhole zonal isolation for many applications due to their cost-effective and interventionless deployment. For drilling long laterals, customers prefer to drill in oil-based muds (OBM) because the OBM acts as a lubricant and helps deeper and faster drilling. The swell packers are deployed in OBMs up to total depths (TD) of 36,000ft and require sufficient time to run liner to bottom, pull out of hole with running string, and run a displacement string to total depth (TD) to displace the OBM mud to a completion brine and breaker prior to the swell packer contacting the 8.5-in. open hole. Thereafter, upon exposure to produced or injected fluid, the packer must hold pressure to a wash out an openhole diameter of 9 in. > 1,000psi. Commercial oil swell packers meet the differential pressure requirements, however, their fast swell rate, especially in high-temperature applications, presents a significant challenge in getting these packers to the required depth/distance. In this paper we report the development and testing of 11-day delay oil swell packers to compartmentalize an 8.5-in. openhole, seal a 9.25-in. washout zone, and hold a minimum differential pressure of 1000psi at 220° F. Swell delay was conducted on 20-in. × 8.15-in. OD donuts (dunk packers) on a base pipe 6.625-in. OD in oil-based mud (NAF) at 200 to 207° F. Pressure testing was performed as per API190H standard on packers (4 ft × 8.15 in. and 5.5 ft × 8.15 in.) on a 6.625-in. base pipe that was pressure tested at 225° F by applying pressure from top and bottom annulus. These packers held a steady differential pressure of 1100 to 1300 psi for 30 minutes. This development enhances the ability to reliably compartmentalize larger open holes with potential washout sections by using a delayed swell oil packer.

Influence of Partially Carboxylated Powdered Lignocellulose from Oat Straw on Technological and Strength Properties of Water-Swelling Rubber

“…The main component of leaves, bromes and stems of annual agricultural plants is cellulose with a small amount of lignin. The advantage of this type of raw material is annual renewability, ease of processing and low cost [ 2 , 3 , 4 , 5 , 6 , 7 ]. It helps to reduce the high dependence on petrochemical resources [ 8 ].…”