Dhruvin Kaneria* and Tirth Raval
For ensuring casing and cementing quality, mud cake removal is essential. Various problems like stuck pipe take place because of the presence of mud cake. Mechanical methods of water jetting and chemical methods by means of acids, oxidizers, chelating agents, etc., are currently employed for mud cake removal. However, water jetting can cause water blockage problems and has detrimental effects on well productivity. Also, mud cakes of different permeability will not be removed by same intensity water jets. Acids and oxidizers are very reactive but nonspecific species, imposing several post perforation problems and formation damage. As an alternative, we propose a new method in this study with the usage of nanobots and laser grinding. The nanobots, placed in carrier, can be deployed in all directions into the targeted zone. These non-adherent and self-propelled nanobots will move through the vertical permeability of the mud filtrate and would interpret the petro physical properties of the mud filtrate. The sensors would then send this data to molecular processor and with the help of radio frequency transmitter and receiver, we could immediately interpret the real time data from every point in the zone of interest. This data would be used to change the intensity of the lasers in accordance with the petro physical properties. Lasers, lowered through wireline, would then vaporise the mud cake through spallation according to its thickness and will grind the mud cake by creating popped holes. This novel idea of real time laser grinding with the help of nanobots holds great potential in removing mud cake precisely and efficiently and could also be useful in multilateral and horizontal wells.