Waterless Cement Slurry Controls Water Production in Southern Mexico Naturally Fractured Oil Wells

Abstract

Water control is one of the greatest challenges in Southern Mexico wells, where the reservoirs are generally fractured carbonates. Many of the wells have early water breakthrough as a result of one or more of the following: water coning, near- wellbore flow, high-conductivity channels, high-conductivity layer breakthrough, segregated layering, and inadequate completions. In cases where it is possible to shut off the producing interval and recomplete the well in a new interval, reticulated polymer gels and/or cement slurries can control water production. However, when the water is produced in a different interval than the oil, the success rate of reducing the water cut is less than 30%. In these cases, waterless cement slurry squeezes have proven to be an effective solution to unwanted water production. This method has been used to successfully reduce water cut in several fields in South Mexico with a nearly 100% success rate. A well which was carefully evaluated as a candidate and then treated with a waterless cement slurry resulted in a reduction in water cut from 71% to 5%, while oil production increased from 290 barrels of oil per day (BOPD) to 1054 BOPD. In addition, the deferred production was greatly reduced using this technique—less than four days compared with several weeks using alternative techniques. Water cement squeezes are a cost-effective way to reduce water production in the producing intervals of naturally fractured reservoirs. This technique has increased oil production while resulting in significant cost savings in terms of both treatment costs and deferred production.

Study on the Mechanisms and Evaluation Methods of Borehole Instabilities in Gas Drilling

“…In addition, existing blockage technologies, including blockage technology of expansion pipe [23] , cement blockage technology [24] and blockage technology by injecting blockage agent, have some defects, for example lax blockage, poor pressure-bearing capacity, complex technology and so on. So it is an important research direction and need to accurately predict the position of fluid producing layer.…”

Production Optimization of an Oil Well by Restraining Water Breakthrough

“…This results in the premature closure of these wells due to production that has become uneconomically profitable. Different techniques have been employed to control the problem of water ingress in oil wells, each type of problem has solution options that extend to mechanical, chemical, and completion solutions [21][22][23][24][25]. Multiple water control problems are common and a combination of these solutions is required.…”

“…The results of successful applications of polymer gels to control undesirable water production in mature fissured reservoirs in northern Italy have been presented in [23]. In several fields in South Mexico, waterless cement slurry squeezes have been proven to be an effective solution to unwanted water production as shown in [24]. In [25], the solution selected to control the water breakthrough in the studied well was a combination of two conformance technologies for water control that permit sealing high permeability channels and fractures and, more importantly, help provide selective water control.…”