What we claimed is:
1. A semiconductor memory device accessible by the use of logical addresses from a host system which divides and manages file data by the use of clusters each of which is composed of a plurality of sectors and is a unit for division and management of the file data, comprising:
a memory section composed of the plurality of sectors, and capable of erasing data stored therein for each block; and
a control section for transforming a logical address received by the host system to a physical address so that a logical address of a head sector of said cluster corresponds to a physical address of a head sector of said block, and for accessing the memory section by the use of the physical address thus transformed.
2. The semiconductor memory device in accordance with claim 1, wherein said logical address is transformed to said physical address by applying an address offset value to said logical address.
3. The semiconductor memory device in accordance with claim 2, wherein a computation of said address offset value is executed by the use of information concerning total storage capacity of said memory section immediately after beginning power supply.
4. The semiconductor memory device in accordance with claim 2, wherein a computation of said address offset value is executed by the use of information concerning a partition prepared on said memory section.
5. The semiconductor memory device in accordance with claim 4, wherein the computation of said address offset value is executed when the information pertaining to said partition is written.
6. The semiconductor memory device in accordance with claim 5, wherein the information pertaining to said partition is data written into an address 0 of said logical address.
7. The semiconductor memory device in accordance with claim 2, wherein a computation of said address offset value is executed by the use of managing information used for managing said file data in a file system prepared on said memory section.
8. The semiconductor memory device in accordance with claim 7, wherein the computation of said address offset value is executed when said managing information is written.
9. An information processing device comprising:
the semiconductor memory device in accordance with any one of claims 1 to 8.
10. A host system which divides and manages file data using clusters each of which is composed of a plurality of sectors and is a unit for division and management of the file data, wherein in accessing a memory device which is composed of a plurality of sectors and is capable of erasing data for each block, a logical address is transformed to a physical address so that a logical address of a head sector of said cluster corresponds to a physical address of a head sector of said block, and then accesses said memory device by the use of the physical address thus transformed.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A well treatment method for treating a formation around a wellbore, the formation having a fracturing pressure, comprising:
(a) transporting a degradable thermoplastic polymer in a solid bulk form down the wellbore;
(b) displacing a polymer-continuous liquid phase comprising the degradable thermoplastic polymer from the wellbore into the formation at a pressure greater than the fracturing pressure of the formation.
2. The method of claim 1 further comprising the step of allowing a time for the degradable polymer to form the polymer-continuous liquid phase in the wellbore.
3. The method of claim 1 wherein the polymer-continuous liquid phase, having a specific gravity, is displaced from the wellbore by a fluid having a lower specific gravity than the specific gravity of the polymer-continuous liquid phase.
4. The method of claim 1 further comprising the step after step (b) of allowing a time for the degradable polymer to degrade.
5. The method of claim 1 further comprising the step of forming a hydraulic fracture in the formation around the wellbore and then performing step (a) and step (b) before closure of the hydraulic fracture.
6. The method of claim 1 further comprising the step of forming a hydraulic fracture in the formation around the wellbore and then performing step (a) and step (b) after closure of the hydraulic fracture.
7. The method of claim 1 further comprising the step of performing another operation in the wellbore after step (b) and before allowing a time for the degradable polymer to degrade.
8. The method of claim 7 wherein the other operation in the wellbore is gravel packing.
9. The method of claim 1 wherein at least a portion of the degradable polymer contains a proppant.
10. The method of claim 1 further comprising the step of transporting ball sealers down the wellbore along with or following the degradable polymer.
11. The method of claim 1 wherein the degradable polymer comprises a water-degradable polymer.
12. The method of claim 11 wherein the water-degradable polymer comprises a polyester.
13. The method of claim 12 wherein the polyester comprises a polylactide.
14. The method of claim 13 wherein the polylactide is poly (D, L-lactide).
15. The method of claim 13 wherein the polylactide is a mixture of isomers having a composition in the range from about 10 per cent D-isomer to about 90 per cent D-isomer.
16. The method of claim 1 wherein the degradable polymer forms a viscous liquid when in contact with water.
17. The method of claim 1 wherein the degradable polymer is degraded by a process of solution in a liquid that is produced from or later injected into the formation.
18. The method of claim 17 wherein the degradable polymer is wax.
19. The method of claim 1 wherein step (a) is performed by forming a slurry of the degradable polymer in a carrier fluid and pumping a displacement fluid down the wellbore following the carrier fluid.
20. The method of claim 1 wherein step (a) is performed by placing the degradable polymer in a carrier fluid in the wellbore and allowing the degradable polymer to fall by gravity down the wellbore.
21. The method of claim 1 wherein the polymer-continuous liquid phase is formed by accumulating the degradable polymer in proximity to one or more perforations in the wellbore.
22. The method of claim 1 wherein the polymer-continuous liquid phase is formed by accumulating the degradable polymer at a selected depth in the wellbore above the formation.
23. The method of claim 1 wherein in step (a) the polymer-continuous liquid phase is pumped from the surface along with a low-viscosity fluid.
24. A method for hydraulic fracturing of a formation penetrated by a wellbore, comprising:
(a) forming a slurry comprising a degradable thermoplastic polymer in a solid form in a carrier fluid and placing the slurry in the wellbore;
(b) with a displacement fluid having a selected specific gravity, displacing the slurry down the wellbore to a selected location in the wellbore;
(c) converting the slurry to a continuous liquid phase having a specific gravity and comprising the carrier fluid dispersed in the degradable polymer at the selected location in the wellbore; and
(d) applying pressure to the displacement fluid, the selected specific gravity of the displacement fluid being less than the specific gravity of the continuous liquid phase, to inject the continuous liquid phase into the formation to form a hydraulic fracture.
25. The method of claim 24 wherein at least a portion of the degradable polymer contains a proppant.