Patent EA-001119-B1 (EA)
Title: A method and an apparatus for use in production tests, testing an expected permeable formation
Inventor: WOIE RUNE
IPC: E21B49/00
Filed: 1998-04-06
Abstract: 1. A method for use in connection with an expected permeable, first formation (4), where fluid flowing out therefrom, during the production test is subjected to i.a. pressure measurement and flow rate control, characterized in that at least one defined fluid flowing path (8) is established between said expected permeable, first formation (4) and a permeable, second formation (6), and that fluid flowing out from said first formation (4) is conducted through said fluid flowing path (8) to said second formation (6) which receives this fluid and keeps it at least temporarily. 2. A method according to claim 1,chaaracterized in that the fluid flowing path(s) is(are) established by means of channel-forming pipe(s) (8) which is positioned preferably concentrically with the surrounding bore hole wall/casing face between first and second formations (4, 6) situated at different levels, and that sealing means (7, 10, 12, 11) are placed in order to prevent fluid from flowing from first formation (4) to second formation (6) outside the fluid flowing path(s) (8). 3. A method according to claim 1 or 2, characterized in that, after fluid has been transferred from first formation (4) to second formation (6), a reversed production test is carried out in that (transferred) fluid is returned forcedly from second formation (6) to first formation (4). 4. A method according to any one of the preceding claims, characterized in that a fracturing of said first formation (4) is carried out, the well in the area of first formation (4) being supplied with pressurised liquid, e.g. through a drill string which is connected to said fluid flowing path (8). 5. An apparatus for carrying out the method as defined in claim 1, and intended to be mounted into a well (1) between two formations, an expected permeable first formation (4) to be production tested, and a second permeable formation (6) comprising for the production test one or more sensors/meters/ regulators/controllers (15, 17) for i.a. sensing/ measuring, recording pressure conditions and flowing rate as well as adjusting the latter, characterized in that the apparatus comprises at least one channel-forming pipe (8) which, within the well (1), establishes a fluid flow path between a first formation (4) to be production tested and a second permeable formation (6), sealing means (7, 10, 11, 12) assigned the apparatus being placed in order to restrict the fluid flow between the formations (4, 6) to take place only in the channel or channels (8) formed to establish at least one restricted fluid flow path, so that this/these channel(s) (8) constitutes the only fluid communication between the two permeable formations (4, 6). 6. An apparatus according to claim 5, characterized in that said channel-forming pipe (8), respectively each channel-forming pipe (8), is open at the end situated closest to the formation (4) to be production tested, but closed at the opposite end, where an adjacent pipe portion situated within said second formation (6) has one or more lateral, through-going gates (13). 7. An apparatus according to claim 5, characterized in that the channel-forming pipe (8), respectively each pipe (8), has closed axial ends, and that they, adjacent each end portion, within an area surrounded by the respective formation (4, 6), has one or more lateral, through-going gates (21). 8. An apparatus according to claim 5, characterized in that each through-going lateral gate (21 respectively 13) in each portion of the channel forming pipe (8), respectively each pipe (8), surrounded by one of the formations (4 respectively 6), is assigned a movable, perforated sleeve (14) which, upon displacement in relation to lateral gate (21 respectively 13) in the channel-forming pipe, respectively each such pipe (8), can provide unthrottled or throttled ingoing/outgoing flow of fluid, respectively closure of the fluid flow. 9. An apparatus according to any one of the claims 5-8, characterized in that the channel- forming pipe (8), respectively each channel-forming pipe (8), is assigned a motor-driven pump means (18), preferably a reversible pump means, for forced displacement of the fluid between the formations (4, 6). 10. An apparatus according to any one of the claims 5-9, characterized in that the channel-forming, fluid flow path establishing pipe (8) is assigned a remotely operable valve adapted to control and adjust a fluid flow through the channel (8).