Apparatus for testing earth formations composed of particles of various sizes

Claim 2

Formation-testing apparatus adapted for suspension in a borehole having mudcake lining the walls thereof adjacent to earth formations containing producible connate fluids and comprising: a body having a fluid passage adapted to receive connate fluids; fluid-admitting means on said body including a fluid entry adapted to be engaged with a borehole wall for isolating a surface thereof from borehole fluids; means selectively operable for positioning said fluid-admitting means against a borehole wall to place said fluid entry into communication with earth formations beyond an isolated borehole wall surface; and selectively-positionable fluid-filtering means cooperatively arranged in fluid communication between said fluid passage and said fluid entry and operatively movable upon engagement of said fluid-admitting means with an isolated borehole wall surface to one filtering position for initially passing mudcake particles displaced from an isolated borehole waLl surface on through said filtering means into said fluid passage and operatively movable toward another filtering position whenever loose formation particles are eroded from an isolated borehole wall surface for collecting such loosened formation particles in said fluid entry as connate fluids pass on through said filtering means into said fluid passage.

Claim 3

The formation-testing apparatus of claim 1 wherein said fluid-filtering means include: first and second filtering members respectively provided with first and second filter openings and cooperatively arranged for movement relative to one another between said one filtering position wherein said filter openings mutually define at least one enlarged filter passage sufficient to pass enlarged mudcake particles and said other filtering position wherein said filter openings mutually define at least one reduced filter passage sufficient to retain loose formation particles.

Claim 4

The formation-testing apparatus of claim 2 wherein said first and second filter openings are all at least substantially the same size.

Claim 5

The formation-testing apparatus of claim 2 wherein said first and second filter openings are elongated slits at least substantially the same size.

Claim 6

The formation-testing apparatus of claim 1 wherein said fluid-filtering means include: first and second filtering members respectively provided with first and second filter openings and cooperatively arranged for movement relative to one another between said one filtering position wherein said filter openings are at least substantially aligned with one another to mutually define at least one enlarged filter passage sufficient to pass enlarged mudcake particles and said other filtering position wherein said filter openings are at least partially misaligned with one another to mutually define at least one reduced filter passage sufficient to retain loose formation particles.

Claim 7

The formation-testing apparatus of claim 5 wherein said first and second filter openings are all at least substantially the same size.

Claim 8

The formation-testing apparatus of claim 5 wherein said first and second filter openings are elongated slits at least substantially the same size.

Claim 9

The formation-testing apparatus of claim 1 wherein said fluid-filtering means include: first and second filtering members respectively provided with a plurality of filter openings and cooperatively arranged within said fluid-admitting means to the rear of said fluid entry for longitudinal movement of said first filtering member relative to said second filtering member between said one filtering position wherein each associated pair of said filter openings in said filtering members mutually define an enlarged filter passage sufficient to pass enlarged mudcake particles and said other filtering position wherein each associated pair of said filter openings in said filtering members mutually define a reduced filter passage sufficient to retain loose formation particles; first means coupled to said first filtering member and adapted to engage an isolated borehole wall surface for shifting said first filtering member to said one filtering position upon engagement of said fluid-admitting means with an isolated borehole wall surface; and second means coupled to said first filtering member and adapted for shifting said first filtering member to said other filtering position upon disengagement of said first means from an isolated borehole wall surface.

Claim 10

The formation-testing apparatus of claim 8 further including: means selectively operable after disengagement of said fluid-admitting means from an isolated borehole wall surface for displacing from said fluid entry any loosened formation particles previously collected in said fluid entry.

Claim 11

The formation-testing apparatus of claim 8 further including: pressure-measuring means coupled to said fluid passage and adapted for providing at least one measurement representative of the pressure of connate fluids in sAid fluid passage.

Claim 12

The formation-testing apparatus of claim 8 further including: sample-collecting means on said body and selectively operable for obtaining a sample of connate fluids in said fluid passage.

Claim 13

The formation-testing apparatus of claim 8 further including: pressure-measuring means coupled to said fluid passage and adapted for providing at least one measurement representative of the pressure of connate fluids in said fluid passage; and sample-collecting means on said body and selectively operable for obtaining a sample of connate fluids in said fluid passage.

Claim 14

The formation-testing apparatus of claim 12 further including: means selectively operable after disengagement of said fluid-admitting means from an isolated borehole wall surface for displacing from said fluid entry any loosened formation particles previously collected in said fluid entry.

Claim 15

Formation-testing apparatus adapted for suspension in a borehole having mudcake lining the walls thereof adjacent to earth formations containing producible connate fluids and comprising: a body having a fluid passage adapted to receive connate fluids; fluid-admitting means on said body and including a fluid-sampling member having a tubular inlet passage adapted to be engaged with a borehole wall for isolating a surface thereof from borehole fluids and an outlet passage downstream of said inlet passage and coupled to said fluid passage, and means on said fluid-sampling member defining a chamber upstream of said outlet passage and adapted for collecting loose formation particles entering said inlet passage; means selectively operable for positioning said fluid-sampling member against a borehole wall to place said inlet passage into communication with earth formations therebeyond; and filtering means on said fluid-sampling member for intercommunicating said inlet and outlet passages and including first and second filtering members respectively having first and second filter openings each selectively sized to pass mudcake particles and cooperatively arranged between said inlet and outlet passages for sliding movement of said first filtering member across said second filtering member between a first position wherein said first and second filter openings mutually define a corresponding number of enlarged filtering passages sufficient to pass enlarged mudcake particles and a second position wherein said first and second filter openings mutually define a corresponding number of reduced filtering passages sufficient to retain loose formation particles, means cooperatively arranged between said filtering members for respectively defining said first and second positions, first actuating means cooperatively arranged for shifting said first filtering member to said first position in response to engagement of said fluid-admitting means with a borehole wall to allow mudcake particles displaced therefrom into said fluid-sampling member to pass readily through said enlarged filtering passages into said outlet passage, and second actuating means cooperatively arranged for shifting said first filtering member to said second position in response to displacement of loose formation particles into said fluid-sampling member from a borehole wall engaged thereby.

Claim 16

Formation-testing apparatus adapted for suspension in a borehole having mudcake lining the walls thereof adjacent to earth formations containing producible connate fluids and comprising: a body having a fluid passage adapted to receive connate fluids; fluid-admitting means on said body and including a fluid-sampling member having a tubular inlet passage adapted to be engaged with a borehole wall for isolating a surface thereof from borehole fluids and an outlet passage downstream of said inlet passage and coupled to said fluid passage, and means on said fluid-sampling member defining a chamber upstream of said outlet passage and adapted for collecting loose formation particles entering said inlet passage; means selectively operable for positioning said fluid-sampling member against a borehole wall to place said inlet passage into communication with earth formations therebeyond; and filtering means on said fluid-sampling member for intercommunicating said inlet and outlet passages and including first and second filtering members respectively having first and second filter openings each selectively sized to pass mudcake particles and cooperatively arranged between said inlet and outlet passages for sliding movement of said first filtering member across said second filtering member between a first position wherein said first and second filter openings mutually define a corresponding number of enlarged filtering passages sufficient to pass enlarged mudcake particles and a second position wherein said first and second filter openings mutually define a corresponding number of reduced filtering passages sufficient to retain loose formation particles, means cooperatively arranged between said filtering members for respectively defining said first and second positions, first actuating means cooperatively arranged for shifting said first filtering member to said first position in response to engagement of said fluid-admitting means with a borehole wall to allow mudcake particles displaced therefrom into said fluid-sampling member to pass readily through said enlarged filtering passages into said outlet passage, and second actuating means cooperatively arranged for shifting said first filtering member to said second position in response to displacement of loose formation particles into said fluid-sampling member from a borehole wall engaged thereby.

Claim 17

The formation-testing apparatus of claim 14 further including: pressure-measuring means coupled to said fluid passage and adapted for providing at least one measurement representative of the pressure of connate fluids in said fluid passage.

Claim 18

The formation-testing apparatus of claim 14 further including: sample-collecting means on said body and selectively operable for obtaining a sample of connate fluids in said fluid passage.

Claim 19

The formation-testing apparatus of claim 14 further including: pressure-measuring means coupled to said fluid passage and adapted for providing at least one measurement representative of the pressure of connate fluids in said fluid passage; and sample-coLlecting means on said body and selectively operable for obtaining a sample of connate fluids in said fluid passage.

Claim 20

The formation-testing apparatus of claim 14 further including: a piston member coaxially arranged in said fluid-sampling member for movement between a retracted position in a rearward portion thereof to close off the rear of said particle-collecting chamber and an extended position in a forward portion of said fluid-sampling member; and means coupled to said piston member and selectively operable for moving said piston member to its said retracted position following engagement of said fluid-admitting means with a borehole wall to admit connate fluids into said fluid-sampling member and for moving said piston member to its extended position following disengagement of said fluid-admitting means from a borehole wall to displace any loosened formation materials previously collected in said particle-collecting chamber from said fluid-sampling member.

Claim 21

Formation-testing apparatus adapted for suspension in a borehole having mudcake lining the walls thereof adjacent to earth formations containing producible connate fluids and comprising: a body having a fluid passage adapted to receive connate fluids; fluid-admitting means on said body and including a fluid-sampling member having a tubular forward portion defining an inlet passage adapted to be engaged with a borehole wall for isolating a surface thereof from borehole fluids, and an outlet passage coupled to said fluid passage and having an inwardly-facing entrance in said tubular forward portion downstream of said inlet passage; means selectively operable for positioning said fluid-sampling member against a borehole wall to establish communication with earth formations therebeyond; filtering means between said inlet and outlet passages adapted for limiting the entrance of loose formation particles into said fluid passage and including a fixed filtering member having a plurality of filter openings covering said outlet passage entrance, a movable filtering member having a plurality of filter openings complementally fitted over said fixed filtering member and adapted for movement relative thereto between one position where said filter openings in each of said filtering members mutually define a corresponding number of enlarged filtering passages sufficient to pass mudcake particles and another position where said filter openings in each of said filtering members mutually define a corresponding number of reduced filtering passages sufficient to retain loose formation particles, first means cooperatively arranged on said fluid-sampling member and operable for moving said movable filtering member toward its said one position upon engagement of said fluid-sampling member with a borehole wall to allow mudcake particles displaced therefrom into said fluid-sampling member to pass readily through said enlarged filtering passages into said outlet passage, and second means cooperatively arranged on said fluid-sampling member for moving said movable filtering member toward its said other position in response to displacement of loose formation materials into said fluid-sampling member from a borehole wall engaged thereby; and means adapted for controlling the entrance of particles into said fluid-sampling member and including a piston member coaxially arranged in said fluid-sampling member for movement past said filtering members between an advanced position within said tubular forward portion ahead of said filter openings blocking communication into said fluid-sampling member and a retracted position to the rear of said filter openings for uncovering said filtering members and defining a space to the rear thereof for collecting loosened formation particles entering said tubular forward portion, and piston-control means cooperatively arranged for selectively moving said piston member back and forth between its said advanced and retracted positions.

Claim 22

Formation-testing apparatus adapted for suspension in a borehole having mudcake lining the walls thereof adjacent to earth formations containing producible connate fluids and comprising: a body having a fluid passage adapted to receive connate fluids; fluid-admitting means on said body and including a fluid-sampling member having a tubular forward portion defining an inlet passage adapted to be engaged with a borehole wall for isolating a surface thereof from borehole fluids, and an outlet passage coupled to said fluid passage and having an inwardly-facing entrance in said tubular forward portion downstream of said inlet passage; means selectively operable for positioning said fluid-sampling member against a borehole wall to establish communication with earth formations therebeyond; filtering means between said inlet and outlet passages adapted for limiting the entrance of loose formation particles into said fluid passage and including a fixed filtering member having a plurality of filter openings covering said outlet passage entrance, a movable filtering member having a plurality of filter openings complementally fitted over said fixed filtering member and adapted for movement relative thereto between one position where said filter openings in each of said filtering members mutually define a corresponding number of enlarged filtering passages sufficient to pass mudcake particles and another position where said filter openings in each of said filtering members mutually define a corresponding number of reduced filtering passages sufficient to retain loose formation particles, first means cooperatively arranged on said fluid-sampling member and operable for moving said movable filtering member toward its said one position upon engagement of said fluid-sampling member with a borehole wall to allow mudcake particles displaced therefrom into said fluid-sampling member to pass readily through said enlarged filtering passages into said outlet passage, and second means cooperatively arranged on said fluid-sampling member for moving said movable filtering member toward its said other position in response to displacement of loose formation materials into said fluid-sampling member from a borehole wall engaged thereby; and means adapted for controlling the entrance of particles into said fluid-sampling member and including a piston member coaxially arranged in said fluid-sampling member for movement past said filtering members between an advanced position within said tubular forward portion ahead of said filter openings blocking communication into said fluid-sampling member and a retracted position to the rear of said filter openings for uncovering said filtering members and defining a space to the rear thereof for collecting loosened formation particles entering said tubular forward portion, and piston-control means cooperatively arranged for selectively moving said piston member back and forth between its said advanced and retracted positions.

Claim 23

The formation-testing apparatUs of claim 19 wherein said outlet passage entrance is defined by an annular chamber formed around an interior wall portion of said fluid-sampling member between said advanced and retracted positions of said piston member; and said filtering members are respectively tubular members coaxially mounted in said fluid-sampling member around said annular chamber with said movable filter member being sized for passage of said piston member as it moves between its said positions.

Claim 24

The formation-testing apparatus of claim 19 wherein said filter openings are respectively comprised of a plurality of circumferentially-oriented slits spaced longitudinally along each of said filter members with the width of each of said slits being selectively sized for passage of mudcake particles, and wherein the movement of said movable filtering member is longitudinally in relation to said fluid-sampling member.

Claim 25

The formation-testing apparatus of claim 21 wherein the distance between said positions of said movable filtering member is selected so that each of said slits in said movable filtering member is always cooperatively associated with the same one of said slits in said fixed filtering member.

Claim 26

The formation-testing apparatus of claim 19 further including: sealing means cooperatively arranged on said fluid-admitting means around said tubular forward portion and adapted for packing-off a borehole wall around said tubular forward portion.

Claim 27

The formation-testing apparatus of claim 19 further including: means cooperatively mounting said fluid-sampling member on said body for movement relative thereto between a laterally-extended position and a retracted position; and control means cooperatively arranged for selectively moving said fluid-sampling member back and forth between its said extended and retracted positions.

Claim 28

The formation-testing apparatus of claim 19 further including: sample-receiving means on said body and adapted for receiving filtered connate fluids entering said fluid passage; and control means cooperatively arranged for selectively coupling said sample-receiving means to said fluid passage.

Claim 29

The formation-testing apparatus of claim 19 further including: pressure-monitoring means for providing indications at the surface indicative of the pressure of connate fluids in said fluid passage.

Claim 30

The formation-testing apparatus of claim 19 further including: a wall-engaging member movably mounted on said body on the opposite side thereof from said forward portion of said fluid-sampling member; and piston means cooperatively coupled to said wall-engaging member for moving said wall-engaging member between an extended wall-engaging position and a retracted position against said opposite body side to respectively engage and disengage said fluid-admitting means with and from a borehole wall.

Claim 31

The formation-testing apparatus of claim 19 further including: means cooperatively coupling said fluid-sampling chamber to said body for movement relative to one side thereof between a laterally-extended position and a retracted position; and piston means cooperatively coupled to said fluid-sampling member for moving said fluid-sampling member between its said laterally-extended position and its said retracted position to respectively engage and disengage said fluid-sampling member with and from a borehole wall.

Claim 32

The formation-testing apparatus of claim 28 further including: a wall-engaging member movably mounted on said body on the opposite side thereof; and piston means cooperatively coupled to said wall-engaging member for moving said wall-engaging member between an extended wall-engaging position and a retracted position against said opposite body side upon movement of said fluid-sampling member between its said positions.