A method and a centralizer system for centralizing a casing in a well bore

Abstract

A centralizer system and a method for centralizing a casing in a well bore before cementing of the casing in the well bore is disclosed, where the centralizer system comprises at least one centralizer which is adapted for mounting on the casing where the at least one centralizer comprises a receiving unit capable of receiving a wireless signal in form of a pressure wave and a wireless signal generator for generation and transmission of a wireless signal in form of a pressure wave which the receiving unit of the at least one centralizer is capable of receiving. The at least one centralizer is further configured such that the centralizer is activated for centralizing of the casing when the receiving unit receives a wireless signal transmitted by the signal generator.

1 . Method for centralizing a casing in a well bore before cementing of the casing in the well bore, the method comprising the steps of:
 mounting at least one centralizer on the casing, the at least one centralizer comprising a receiving unit capable of receiving a wireless signal in form of a pressure wave,   positioning the casing in the well bore at a desired position,   providing a wireless signal generator for generation and transmission of a wireless signal in form of a pressure wave which the receiving unit of the at least one centralizer is capable of receiving, and   transporting the signal generator down the well bore towards the casing and activating the signal generator such that the signal generator transmits the wireless signal and whereafter the receiving unit, on reception of the wireless signal, activates the at least one centralizer and the at least one centralizer centralizes the casing in the well bore.   
     
     
         2 . Method according to  claim 1 , wherein a transport element is transported down the well bore, the transport element comprising the signal generator. 
     
     
         3 . Method according to one of the  claims 1 - 2 , wherein the signal generator is triggered to start transmitting the wireless signal as the signal generator is approaching the casing or upon arrival at the casing. 
     
     
         4 . Method according to  claim 1 , wherein the signal generator is triggered to start transmitting said wireless signal when the pressure in the well fluids surrounding the at least one transport element exceeds a predetermined value. 
     
     
         5 . Method according to  claim 1 , wherein the signal generator is triggered to start transmitting said wireless signal when the temperature in the well fluids surrounding the at least one transport element exceeds a predetermined value. 
     
     
         6 . Method according to  claim 1 , wherein the signal generator is mechanically triggered to start transmitting said wireless signal when the signal generator arrives at the casing. 
     
     
         7 . Method according one of the  claims 1 - 2 , wherein the signal generator in the transport element continuously or intermittently transmits the wireless signal while being transported through the well bore. 
     
     
         8 . Method according to  claim 1 , wherein a plurality of centralizers are provided in the well bore and that the centralizers are signally connected such that when the receiving unit of a first centralizer receives said wireless signal, the signal is forwarded to at least one of the remaining centralizers which will initiate centralizing of the casing on which it is mounted. 
     
     
         9 . Method according to  claim 1 , wherein the pressure wave is a sound signal. 
     
     
         10 . Method according to  claim 1 , wherein the transport element is pumped down the well bore by cement slurry. 
     
     
         11 . Method according to  claim 1 , wherein transport element is a viper plug. 
     
     
         12 . A centralizer system for centralizing a casing in a well bore before cementing of the casing in the well bore, the centralizer system comprising:
 at least one centralizer which is adapted for mounting on the casing, the at least one centralizer comprising a receiving unit capable of receiving a wireless signal in form of pressure waves,   a wireless signal generator which is adapted for transport down the well bore and for generation and transmission of a wireless signal in form of a pressure wave which the receiving unit of the at least one centralizer is capable of receiving, and   wherein the at least one centralizer is configured such that the centralizer is activated for centralizing of the casing when the receiving unit receives a wireless signal transmitted by the signal generator.   
     
     
         13 . Centralizer system according to  claim 12 , wherein the centralizer system comprises a transport element, the transport element comprising the signal generator. 
     
     
         14 . Centralizer system according to one of the  claims 12 - 13 , characterized in that the centralizer system comprises a pressure sensor comprised in the signal generator or the transport element, the signal generator being adapted to be activated when the pressure in the well bore exceeds a predetermined value. 
     
     
         15 . Centralizer system according to one of the  claims 12 - 14 , characterized in that the centralizer system comprises a temperature sensor comprised in the signal generator or the transport element, the signal generator being adapted to be activated when the temperature in the well bore exceeds a predetermined value. 
     
     
         16 . Centralizer system according to one of the  claims 12 - 14 , characterized in that the at least one centralizer and/or the signal generator and/or the transport element is provided with a mechanical device which activates the signal generator when the signal generator arrives at the casing. 
     
     
         17 . Centralizer system according to one of the  claims 12 - 15 , characterized in that the centralizer system comprises a plurality of centralizers and that the centralizers are signally connected such that when the receiving unit of a first centralizer receives said wireless signal, the signal is forwarded to at least one of the remaining centralizers which will initiate centralizing of the casing on which it is mounted. 
     
     
         18 . Centralizer system according to one of the  claims 12 - 17 , characterized in that the pressure wave is a sound signal. 
     
     
         19 . Centralizer system according to one of the  claims 12 - 18 , characterized in that the transport element is a viper plug. 
     
     
         20 . Use of a wireless signal to initiate the centralizing of a casing in a well bore before cementing of the casing, wherein the wireless signal is in the form of a pressure wave. 
     
     
         21 . Use of a wireless signal according to claim  24 , wherein the pressure wave is a sound wave.