Patent Application
20150337655
This disclosure pertains generally to investigations of underground formations and more particularly to devices and methods for sampling fluids in a borehole.
Commercial development of hydrocarbon producing fields requires significant amounts of capital. Before field development begins, operators desire to have as much data as possible in order to evaluate the reservoir for commercial viability. Therefore, numerous tests are performed during and after drilling of a well in order to obtain data regarding the nature and quality of the formation fluids residing in subsurface formations. As is known, the quality of the samples obtained during these tests heavily influences the accuracy and usefulness of the test results.
In one aspect, the present disclosure addresses the need to obtain pristine fluid samples from a subsurface formation.
In aspects, the present disclosure provides an apparatus for retrieving a fluid from a sampling zone in a borehole intersecting a formation. The apparatus may include a sampling tool having a port positioned in the sampling zone and a permeable media filling an annular space surrounding the port. The permeable media may include a circumferential support face contacting a borehole wall, the support face extending axially and uniformly along a length of the sampling zone, a first plurality of radial flow channels conveying fluid between the borehole wall and the port, and a second plurality of radial flow channels conveying fluid between the borehole wall and a location isolated from the port.
Examples of certain features of the disclosure have been summarized rather broadly in order that the detailed description thereof that follows may be better understood and in order that the contributions they represent to the art may be appreciated.
For a detailed understanding of the present disclosure, reference should be made to the following detailed description of the embodiments, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals, wherein:
In aspects, the present disclosure relates to devices and methods for providing enhanced sampling of formation fluids. The teachings may be advantageously applied to a variety of systems both in the oil and gas industry and elsewhere. Merely for clarity, certain non-limiting embodiments will be discussed in the context of tools configured for borehole uses.
Referring initially to
The downhole assembly 30 may include a fluid testing module 50. The module 50 may include a sealing element 52 and a fluid port 54. A permeable media 56 fills an annular space 58 surrounding the fluid port 54. The permeable media 56 may be constructed to allow flow only in the plane perpendicular to a longitudinal axis 60 of the module 50. For instance, the permeable media 56 may include multiple layers of passages that fan radially outward from the longitudinal axis 60. Each layer of passages may be hydraulically isolated from an adjacent layer of passages. Segregating fluid in layers of passages transverse to the axis 60 may aid in sampling only the fluid of choice 64 using the fluid port 54.
Referring to
In one arrangement, the fluid ports 80a-c may be configured to generate a primary and a secondary fluid inflow. For example, fluid port 80a may cause a primary fluid inflow for acquiring samples of the formation fluid. Fluid ports 80b,c may cause secondary fluid inflows that reduce contamination of the primary fluid inflow. The ports 80a-c may be connected via lines 82a, b to a suitable fluid mover, such as pumps (not shown). The fluid ports 80a-c may be selectively operated to flow into one or more of the ports 80a-c simultaneously. In one arrangement, the fluid inflow from port 80a may be directed into a sample tank (not shown). The fluid inflows into port 80b, c may be pumped out to the borehole 12.
The permeable media 56 may include a circumferential support face 84 contacting a borehole wall 86, a first set of radial flow channels 86, and a second set of radial flow channels 88. The support face 84 extends axially and uniformly along a length of the sampling zone 70. The support face 84 acts as a vertical perforated wall that prevents the rock and earth making up the borehole wall 86 from collapsing into the sampling zone 70. The first set of radial flow channels 86 conveys fluid between the borehole wall 86 and the port 80a. The second set of radial flow channels 88 conveys fluid between the borehole wall and a location isolated from the port 80a. As shown, these isolated locations may be ports 80b, c.
In embodiments, the permeable media 56 may be a toroid defined by the outer circumferential support face 84, an inner circumferential face 85, and upper and lower faces 89a, b. It should be noted that the body of the permeable media 56 is substantially contiguous along the borehole wall 86. Additionally, the inner circumferential face 85 covers the ports 80a-c. Thus, fluid in the sampling zone 70 must flow through the inner circumferential face 85 to enter the ports 80a-c. It should also be noted that each port 80a-c is in fluid communication with the borehole wall 86 via a plurality of flow passages 72.
Referring now to
Referring to
In other variants, the permeable media 56 may be formed in a manner similar to an umbrella. Thus, the blades 100 may be canopies that attached to ribs. The canopies may be expanded by a stretcher and runner assembly. In still other embodiments, the permeable media 56 may be formed in an accordion shape.
Referring to
In still another embodiment, the permeable media 56 may include injectable material such as a foam or gel that solidifies after being injected into the sampling zone. The injectable material may be anisotropic. The injectable material may be mechanically broken up after use or dissolved by a suitable solvent.
Referring now to
Now, pumps (not shown) may be activated to draw fluid through the permeable media 56. The fluid entering the sampling zone 70 are confined to a laminar flow wherein a fluid along one radial path does not comingle with the fluid flowing along an axially adjacent radial flow path. Thus, the radial flow passages are hydraulically isolated from one another while in the sampling zone 70. Thus, the supplemental ports 80b, c draw away fluid that would otherwise comingle with the fluid entering the ports 80a.
While a wireline conveyance system has been shown, it should be understood that embodiments of the present disclosure may be utilized in connection with tools conveyed via rigid carriers (e.g., jointed tubular or coiled tubing) as well as non-rigid carriers (e.g., wireline, slick line, e-line, etc.). Some embodiments of the present disclosure may be deployed along with Logging While Drilling/Measurement While Drilling (LWD/MWD) tools.
While the foregoing disclosure is directed to the one mode embodiments of the disclosure, various modifications will be apparent to those skilled in the art. It is intended that all variations be embraced by the foregoing disclosure.
