Single toe sleeve increases return on investment
Challenge – In horizontal wells, a toe sleeve is used to provide the necessary access from the wellbore to the formation at the toe of the well. Communication between the wellbore and the formation is needed to provide a flow path that will allow displacing either frac plugs and/or frac balls downhole so that multistage fracturing operations can commence. This initial flow path might also be used to place the first stimulation treatment, thus additional reserves can be reached from the subject wellbore. In order to get the right balance between the required pumping rate to create a fracture and the allowable pump pressure, enough flow area must be provided at the wellbore/formation communication point. Due to their design, some toe sleeves are not able to fully expose all the stimulation ports. This creates restriction to flow and high pumping pressure at a low pumping rate, hindering the operator’s ability to create a fracture through the toe sleeve.
Some operators have found it challenging to achieve the rate needed in order to stimulate the toemost stage with a single toe sleeve. Reduced pump rates can occur if a toe sleeve does not slide all the way open or if a burst disk or toe sleeve does not expose all ports due to pressure equalization. For this reason, it has often been necessary to use multiple sleeves at the toe of the well in order to achieve the desired pumping rate. This increases the cost since it requires two or three sleeves to achieve the rates needed to correctly stimulate the toe portion of the lateral.
Production from a toe stage becomes an additional concern after a stimulation is placed through a sleeve. Pumping a stage through a sleeve creates additional time and costs, which production return will need to outweigh.
Solution – The Halliburton 5½-in. RapidStart® Initiator CT sleeve design helps ensure that the sleeve will fully expose all flow port areas. The provided flow area allows a pumping crew to achieve the fracturing pumping rate through a single toe sleeve. Hydrocarbon and water tracers were used on four separate wells to ensure the additional cost and time for the stage were worth the investment.
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