| Autor: |
Rajendra A. Kalgaonkar, Khalid Alnoaimi, Vikrant Wagle, Ismail Alhussain |
| Rok vydání: |
2017 |
| Předmět: |
|
| Zdroj: |
Day 1 Mon, November 13, 2017. |
| DOI: |
10.2118/188322-ms |
| Popis: |
Conformance sealants are widely used in the oil industry to prevent unwanted water production. Though a variety of chemicals are used by the industry to control water production, most of them are not accepted in the regions with strict environmental regulations. This paper provides development of a novel plugging and sealing system for the water or gas producing zones. The newly developed conformance sealant is based on a delayed activation chemistry to gel up nanomaterial based dispersion. The nanomaterial used in this study is environmentally benign. The activator which are used in this study to gel up nano material enables the conformance pill to be precisely placed in to the target zone, before the nano material dispersion gels up thus avoiding premature plugging of pipe lines, coiled tubing or other tubulars. The newly developed system can effectively prevent water and gas flow with BHST up to 300°F. The static gelation times were evaluated at different temperatures up to 300°F. An increase in temperature causes increase in the particle collision leading to lower gelation times. The effects of concentration and particle size of activators on gelation times of the new conformance system over a range of temperatures have also been studied. We report the effect of surface charge modification of the nanomaterials on their ability to effectively seal the target zone. The effect of shear rate on geling time of the conformance sealant was also evaluated. Different activators ranging from inorganic to organic were investigated for their effect on the gelation properties of the nanomaterials. The plugging efficiency of the new system was evaluated using coreflood studies. It was shown that the gelation time of the conformace sealant can be controlled by surface charge modification as well as by adjusting the concentration of the activator, which is advantageous as it allows the sealant to remain pumpable over predictable periods of time. The system can effectively prevent unwanted water production. It gives a predictable and controllable pumping time, ranging from a few minutes to several hours at over a wide range of temperatures. This is an important advantage of the present invention as it allows the sealant to remain pumpable for sufficient time for placement and develops the network structure that leads to gelation, over a predictable period of time. The set gel appears as a crystalline solid. It could remain homogenous and stay in place under confined conditions, such as fractures and pore spaces. The novelty of the newly developed sealant is to have a controllable gelation time under a variety of downhole conditions to allow accurate placement without premature plugging inside the wellbore. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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