METHOD FOR REMOTE REGISTRATION OF DOWN HOLE PARAMETERS

Abstract: Method for remote monitoring and registration of down hole parameters in offshore wells comprising provision of a down hole unit (1) having a pressure registration means, a power supply device and a transmitter device. The unit is arranged above a perforated portion of the casing (2), with the perforated portion being arranged in an area comprising a reservoir (4) in such a way that pressure changes in the reservoir will be registered by the unit (1), thereafter transmitted from a unit by electromagnetic waves to a sea bed signal receiving and connection unit (9) from which the signals are transferred to a receiving and processing unit provided on a surface vessel. In the surface vessel unit the signals are decoded, processed and recorded, they are giving information of possible connections between said reservoir and a reservoir in a production well where tests are performed. The recorded information contributes substantially to the knowledge of reservoir communications according to the time and level at which pressure changes are registered in the observation well after known pressure changes in the production well.

Description: Method for remote registration of down hole parameters This invention is related to a method for remote monitoring and registration of down hole parameters in offshore exploration and production wells. Down hole parameters from exploration wells may have considerable importance for the understanding of the reservoar condition and corresponding parameters from a production well substantially will extend the understanding of the pressure maintance of the reservoar and its long run behavior. Down hole parameters of interest may be down hole pressure and temperature and the changes of such parameters during time. During production testing of an offshore well it will be of importance to investigate if there are any con¬ nections between the reservoar of the well to be tested and reservoars in possible adjacent, temporarily abandoned exploration wells. If such a communication exists, analyzes of this connection will contribute to increase the under¬ standing of the reservoar conditions considerably. On the other hand monitoring of the pressure and temperature conditions in the different wells in a production field significantly will contribute to the understanding of the subterranian information reservoar. Such investigations principally have been possible using two drilling rigs, one of which being situated above the abandonded well. This principal, however, will envolve unacceptable high costs in such a degree that this method will not be used. By the method according to the invention possibili¬ ties are present to investigate if such temporarely aband¬ onded wells do have connections to reservoars in adjacent wells without having directly contact between equipment units. With appropriate equipment installed, such a well may be abandoned to be activated in appropriate situations for furhter analyzes. The method according to the invention makes moni¬ toring and recording of down hole parameters from reser- voars possible at low costs by means of the method as de¬ scribed in the characterizing clause of the claims. In the drawings Fig. 1 discloses a section through a formation comprising reservoars and production and obser- vation wells, Fig. 2 discloses a formation section includ¬ ing one reservoar and a surface platform and Fig. 3 sche¬ matically discloses a section through a well and the seabed equipment. Principally the method according to the invention may be used for monitoring down hole parameters in obser¬ vation wells due to changes in the parameters of a product¬ ion well to give a better general understanding of the reservoar communications in the field and in the same way for registing possible connections between reservoars in a well to be production tested and a remote, temporarely abandoned well. Down hole and observation well or an abandoned well respectively a unit 1 is arranged above a portion 11 of the casing 2 having perforations 12 in the area of a reservoar 4. Below the perforations a plug 10 is insert¬ ed. Between the unit 1 and the casing a production plug 6 is inserted thereby establishing a closed portion of the casing 2 connected with the reservoar 4. The unit 1 comprises a pressure registration means, a power supply device and a transmitter device. If communication exists between the reservoar 4 and a reservoar in a remote well being production tested, this operation will cause pressure changes in the casing portion. Due to this pressure changes the pressure regi¬ stration means will submit signals to the transmitter de¬ vice which again will transmit signals partly through the casing 2 and partly through the formation between the re¬ servoar 4 and the sea bed 13. On the sea bed at least one antenna 8 is arranged for receiving such signals, the antenna being connected with a sea bed signal receiving and communication unit 9 from which the signals are transmitted to a surface re¬ ceiving and processing unit (not shown) provided on a sur- face wessel, e.g. a platform. The signal transmission from the sea bed unit 9 may adequartely be performed by transmitting acustic sig¬ nals to the surface vessel or by transmitting electric signals via a cable device 7 to the surface vessel. Based on the time delay between changes in the pressure in the production well and the signals received from correspondingly changed pressures in the observation well, important information is achieved and recorded con¬ cerning possible communication between the two reservoars.

Claims: P a t e n t c l a i m s 1. Method for remote monitoring and registration of down hole parameters in offshore exploration and production wells, CHARACTERIZED IN transmitting down hole parameters signals from an unit (1) comprising a pressure registration means, a power supply device and a transmitted device provi¬ ded down hole above a perforated portion of the well casing (2) in an area having a reservoar formation (4), receiving said signals in a signal receiving and communication unit (9) at the sea bed (13) adjacent the well location, and transmitting the signals to a receiver unit arranged at the sea surface, said receiver unit continously decoding and recording the signals during operation. 2. Method according to claim 1, CHARACTERIZED IN per¬ forming the parameter monitoring in a well situated remote a production testing well for registration of possible reservoar connections. 3. Method according to claim 1, CHARACTERIZED IN per¬ forming the parameter monitoring in a plurality of wells surrounding a production well to be tested. 4. Method according to claim 1-3, CHARACTERIZED IN transmitting electro mechanical signals through the format¬ ion from the down hole transmitting unit (1) to at least one antenna (8) at the sea bed, connected to the signal receiving and communication unit (9), the antenna or anten¬ nas thereby being arranged on the sea bed around the well location. 5. Method according to claim 4, CHARACTERIZED IN transmitting the signals from the sea bed unit (9) through a suitable cable device (7) to the surface unit on the surface vessel. 6. Method according to the claim 4, CHARACTERIZED IN transmitting the signals from the sea bed unit (9) by an acoustic link to the surface unit on the surface vessel.

Inventors: KUMLE PER, KUMLE, PER
Applicants: SAGA PETROLEUM, SAGA PETROLEUM A.S.
Application year: 1985
Main classification: E21B47
IPC codes: E21B47, E21B49