Optimized Commingle Method for Successful Cost Effective Sand Consolidation Treatment

Abstract

Limited production due to maintaining safe drawdown is an inevitable consequence of single target sand consolidation treatment. One of the methods to improve production is by adding a reservoir target to be produced commingle. Sand consolidation quality need to be maintained, meanwhile jobs efficiency still highly demanded.

There are 3 types of commingle treatment strategy. First method was bottom up strategy, it was performed by treating single zone while isolating others. It was performed either by temporary plug isolation or straddle packer. Second method was nitrified treatment; it was performed by mixing sand consolidation treatment with nitrogen in order to boost injection velocity. Third  method was currently developed by optimizing single run – single isolation to perform commingle treatment. In this method, the fluid distribution will be calculated by the reservoir actual injectivity parameter for each targeted reservoir.

The first method was performed on well X with total duration of 20 days with Instantaneous gain of 5.3 MMscfd and well is producing for 11 months until it died. Job cost and operation duration for Well X was approximately double compared to single treatment. The second method was performed on well Y, Gas rate of 1.46 MMscfd is achieved during clean up. Well was producing for total of 30 days after that well was choked up to achieved a higher gas rate but sand burst occurred and well died. The third method was performed on Well A and Well B. The treatment design showed that the bigger the reservoir's physical parameter, the more the volume needed for the reservoir. The injectivity test was performed for both wells, actual reservoir's physical parameter values were known. Thus, it changed the treatment volume and fluid penetration by the previous design. Post-treatment production rate could achieve 4.2 MMscfd for well A and 2.344 MMscfd for well B. Both wells produced without sand. In addition to successful treatment, commingle method can also save operation costs by 40% compared to single treatment. This paper showed that Correct measurement of fluid distribution determines the successful sand consolidation result, proven by comparison of Well A and Well B to Well Y. Production increment and acceleration are also achieved compared to bottom-up perforation strategy. Commingle treatment method opens possibility to produce marginal reserve by reducing operational cost and shorten production period; hence, the well maintenance cost could be minimized during well’s lifetime.