CN117684919A - Marine shale oil and low-permeability reservoir exploitation system and exploitation method - Google Patents
Marine shale oil and low-permeability reservoir exploitation system and exploitation method Download PDFInfo
- Publication number
- CN117684919A CN117684919A CN202311751905.8A CN202311751905A CN117684919A CN 117684919 A CN117684919 A CN 117684919A CN 202311751905 A CN202311751905 A CN 202311751905A CN 117684919 A CN117684919 A CN 117684919A
- Authority
- CN
- China
- Prior art keywords
- well
- production
- oil
- branch
- main
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003079 shale oil Substances 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims description 17
- 238000004519 manufacturing process Methods 0.000 claims abstract description 137
- 239000003921 oil Substances 0.000 claims description 138
- 238000000605 extraction Methods 0.000 claims description 58
- 230000035699 permeability Effects 0.000 claims description 12
- 230000004048 modification Effects 0.000 claims description 9
- 238000012986 modification Methods 0.000 claims description 9
- 239000010779 crude oil Substances 0.000 claims description 6
- 230000008901 benefit Effects 0.000 abstract description 6
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Abstract
The invention relates to an offshore shale oil and low-permeability reservoir exploitation system, which comprises an oil production pipe column assembly, wherein the oil production pipe column assembly comprises an oil production pipe column, the offshore shale oil and low-permeability reservoir exploitation system also comprises a main borehole, a branch oil production borehole and a directional perforation hole, and the main borehole is connected with the branch oil production borehole through the directional perforation hole; the oil production pipe column is provided with a main well hole control tool and a branch well hole control tool, the main well hole control tool is arranged at the main well hole, and the main well hole control tool is configured to communicate or seal the oil production pipe column and the annular flow passage; a branch wellbore control tool is disposed at the branch production wellbore, the branch wellbore control tool configured to open or close the production string. The invention realizes intermittent production of a plurality of wellbores in a single wellbore, increases a single-well control area, improves daily oil production and accumulated oil production of the single well, and improves the economic benefit of the single well of the offshore oilfield.
Description
Technical Field
The invention relates to the technical field of offshore oilfield exploitation, in particular to an offshore shale oil and low-permeability reservoir exploitation system and an exploitation method.
Background
The offshore oil and gas field is in marine environment, production facilities and production wells need to be concentrated on an offshore production platform or a wellhead platform, and due to the limitation of conditions such as huge investment in platform construction and drilling, the offshore oil and gas field can only be developed by adopting a limited number of wells, and the extraction degree, the oil extraction speed and the economical efficiency are limited to a certain extent.
When the offshore shale oil and the low-permeability oil reservoir are developed, the oil gas flows in the reservoir more difficult due to the poor permeability of the reservoir, the daily oil production and the accumulated oil production of a single well of the oil production well are lower, and the economic and effective development is difficult to realize.
Therefore, in the development of offshore shale oil and hypotonic reservoirs, single well production needs to be improved to realize single well high daily production and high cumulative production of the reservoirs, and the development is economical and efficient.
Based on the above problems, there is a strong need for an offshore shale oil and low permeability reservoir recovery system.
Disclosure of Invention
The invention provides an offshore shale oil and low permeability reservoir exploitation system, and aims to at least solve the problem of low yield in the development of the offshore shale oil and low permeability reservoir. In another aspect, the invention provides an offshore shale oil and low permeability reservoir exploitation method.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
the invention provides an offshore shale oil and low-permeability reservoir exploitation system, which comprises an oil production pipe column assembly, wherein the oil production pipe column assembly comprises an oil production pipe column, the offshore shale oil and low-permeability reservoir exploitation system further comprises a main well bore, a branch oil production well bore and a directional perforation hole, and the main well bore is connected with the branch oil production well bore through the directional perforation hole; the oil production pipe column is provided with a main well hole control tool and a branch well hole control tool, the main well hole control tool is arranged at the main well hole, and the main well hole control tool is configured to communicate or seal the oil production pipe column and an annular flow passage; the branch wellbore control tool is disposed at the branch production wellbore, the branch wellbore control tool configured to open or close the production string.
Preferably, the main well control tool comprises a main well packer and a main well electric control switch valve, the main well packer and the main well electric control switch valve are arranged at the bottom of the oil production string assembly, the main well packer is arranged above the main well electric control switch valve, the main well packer is configured to seal the annular flow passage, and the main well electric control switch valve is configured to communicate or seal the oil production string with the annular flow passage.
Preferably, the branch oil extraction well control tool comprises a branch oil extraction well packer and a branch oil extraction well electric control switch valve, the branch oil extraction well packer and the branch oil extraction well electric control switch valve are positioned at the branch oil extraction well, the branch oil extraction well packer is arranged below the branch oil extraction well electric control switch valve, the branch oil extraction well packer is configured to seal the annular flow passage, and the branch oil extraction well electric control switch valve is configured to open or seal the oil extraction production pipe column.
The offshore shale oil and low-permeability oil reservoir exploitation system is characterized in that the oil production pipe column assembly further comprises a power cable, an electric pump unit, a hydraulic control pipeline, a ground control safety valve and a production sliding sleeve, the electric pump unit is arranged on the oil production pipe column through a Y joint, the ground control safety valve is arranged on the oil production pipe column and connected with the hydraulic control pipeline, the power cable is respectively connected with the electric pump unit, the production sliding sleeve is arranged at the bottom of the oil production pipe column, and a main well packer, a main well electric control switching valve, a branch oil production well electric control switching valve and a branch oil production well packer are sequentially arranged on the oil production pipe column below the production sliding sleeve.
In the offshore shale oil and low-permeability oil reservoir exploitation system, preferably, the number of the branched oil exploitation wellbores is not less than 1.
A second aspect of the present invention provides a method for exploiting an offshore shale oil and a low-permeability reservoir, based on the system for exploiting an offshore shale oil and a low-permeability reservoir of any one of claims 1 to 5, specifically, the method is that a main well electric control on-off valve and a branch oil extraction well electric control on-off valve are alternately opened or closed.
In the exploitation method of the offshore shale oil and the low-permeability oil reservoir, preferably, the condition that the main well electric control switch valve is opened is that the main well oil production yield is not lower than the set yield.
In the offshore shale oil and low-permeability reservoir exploitation method, preferably, the condition that the electric control on-off valve of the branch oil exploitation well bore is closed is that the oil exploitation production yield of the branch oil exploitation well bore is lower than the set yield.
In the exploitation method of the offshore shale oil and the low-permeability oil reservoir, preferably, the main well electric control on-off valve and the branch oil extraction well electric control on-off valve are alternately opened or closed, and the method comprises the following specific steps of:
opening and controlling a main well electric control switch valve, and closing an electric control switch valve of a branch oil extraction well, wherein at the moment, stratum crude oil in a main well control area flows into a well shaft through a main well hydraulic fracturing crack, and stratum in a fracturing modification area controlled by the branch oil extraction well enters a seepage storage stage;
when the production yield of the main well oil extraction is lower than the set yield, closing an electric control switch valve for controlling the main well oil extraction and opening an electric control switch valve for controlling the branch well oil extraction, wherein at the moment, the main well control area enters a seepage storage stage, and the stratum crude oil in the fracturing modification area controlled by the branch oil extraction well flows into the well through hydraulic fracturing cracks of the oil extraction branch well;
when the yield of the branch oil extraction well bores is lower than the set yield, closing the electric control on-off valve of the branch oil extraction well bores and opening the electric control on-off valve of the main well bores;
the main well electric control switch valve and the branch oil extraction well electric control switch valve in the steps are repeatedly opened or closed alternately, so that development is completed.
Due to the adoption of the technical scheme, the invention has the following advantages:
the invention realizes intermittent production of a plurality of wellbores in a single wellbore, increases a single-well control area, improves daily oil production and accumulated oil production of the single well, and improves the economic benefit of the single well of the offshore oilfield.
The invention uses two packers and two electric control switch valves to realize intermittent production of the main well hole and the branch well hole of the horizontal well, and has simple structure, convenient implementation and lower cost.
Drawings
FIG. 1 is a schematic diagram of the system of the present invention.
In the figure:
1. a main wellbore; 2. branching an oil recovery wellbore; 3. orienting the perforation holes; 4. branch oil extraction borehole packer;
5. a main wellbore packer; 6. a production string; 7. a power cable; 8. a hydraulically controlled pipeline; 9. an annulus flow passage;
11. hydraulic fracturing cracks of a main well hole; 21. hydraulic fracturing cracks of oil extraction branch wellbores; 61. a ground control safety valve;
62. a Y-joint; 63. an electric pump unit; 64. producing a sliding sleeve; 65. main well electric control switch valve;
66. an electric control switch valve for branch oil extraction well.
Detailed Description
For the purpose of the present invention; the technical scheme and advantages are more clear, and the technical scheme of the invention is clear below with reference to the attached drawings; is fully described. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be noted that the positional or positional relationship indicated by the terms "upper" and "lower" and the like are based on the positional or positional relationship shown in the drawings, and are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.
In the description of the present invention, it should be noted that, unless explicitly stated and limited otherwise, the terms "disposed" and "provided" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
The invention provides an offshore shale oil and low-permeability reservoir exploitation system, which comprises an oil production pipe column assembly, wherein the oil production pipe column assembly comprises an oil production pipe column, the offshore shale oil and low-permeability reservoir exploitation system further comprises a main well bore, a branch oil production well bore and a directional perforation hole, and the main well bore is connected with the branch oil production well bore through the directional perforation hole; the oil production pipe column is provided with a main well hole control tool and a branch well hole control tool, the main well hole control tool is arranged at the main well hole, and the main well hole control tool is configured to communicate or seal the oil production pipe column and an annular flow passage; the branch wellbore control tool is disposed at the branch production wellbore, the branch wellbore control tool configured to open or close the production string. The invention realizes intermittent production of a plurality of wellbores in a single wellbore, increases a single-well control area, improves daily oil production and accumulated oil production of the single well, and improves the economic benefit of the single well of the offshore oilfield.
The following describes in detail an offshore shale oil and low permeability reservoir exploitation system and exploitation method according to an embodiment of the present invention with reference to the accompanying drawings.
Example 1
The offshore shale oil and low-permeability reservoir exploitation system comprises an oil production pipe column assembly, wherein the oil production pipe column assembly comprises an oil production pipe column 6, the offshore shale oil and low-permeability reservoir exploitation system further comprises a main borehole 1, a branch oil production borehole 2 and a directional perforation 3, and the main borehole 1 is connected with the branch oil production borehole 2 through the directional perforation 3; the production string 6 is provided with a main well control tool and a branch well control tool, the main well control tool is arranged at the main well 1, the main well 1 and the branch production well 2 are connected through a directional perforation hole 3, the main well control tool is configured to communicate or seal the production string 6 with an annular flow passage 9, the branch well control tool is arranged at the branch production well 2, and the branch well control tool is configured to open or seal the production string 6 so as to realize that a fracturing modification area controlled by the main well 1 and a fracturing modification area controlled by the branch production well 2 alternately circulate into a seepage storage stage.
The main well control tool comprises a main well packer 5 and a main well electric control switch valve 65, the main well packer 5 and the main well electric control switch valve 65 are arranged at the bottom of the oil production string assembly, the main well packer 5 is arranged above the main well electric control switch valve 65, the main well packer 5 is configured to block the annular flow passage 9, and the main well electric control switch valve 65 is configured to communicate or seal the oil production string 6 with the annular flow passage 9.
The lateral oil extraction well bore control tool comprises a lateral oil extraction well bore packer 4 and a lateral oil extraction well bore electric control switch valve 66, the lateral oil extraction well bore packer 4 and the lateral oil extraction well bore electric control switch valve 66 are positioned at the lateral oil extraction well bore 2, the lateral oil extraction well bore packer 4 is arranged below the lateral oil extraction well bore electric control switch valve 66, the lateral oil extraction well bore packer 4 is configured to seal an annular flow passage 9, and the lateral oil extraction well bore electric control switch valve 66 is configured to open or close an oil extraction production pipe column 9.
When the main well electric control switch valve 65 is opened and the branch oil extraction well electric control switch valve 66 is closed, fluid in the main well 1 enters the oil extraction production string 6 from the annular flow passage 9; when the branch wellbore electric control switching valve 66 is opened and the main wellbore electric control switching valve 65 is closed, the fluid of the branch wellbore 2 directly enters the production string 6.
The oil production pipe column assembly further comprises a power cable 7, an electric pump unit 63, a hydraulic control pipeline 8, a ground control safety valve 61 and a production sliding sleeve 64, wherein the electric pump unit 63 is arranged on the oil production pipe column 6 through a Y joint 62, the ground control safety valve 61 is arranged on the oil production pipe column 6, the ground control safety valve 61 is connected with the liquid level pipeline 8, the power cable 7 is respectively connected with the electric pump unit 63, the production sliding sleeve 64 is arranged at the bottom of the oil production pipe column 6, and a main well hole packer 5, a main well hole electric control switch valve 65, a branch oil production well hole electric control switch valve 66 and a branch oil production well hole packer 4 are sequentially arranged on the oil production pipe column 6 below the production sliding sleeve 64.
Wherein the number of branch oil extraction wellbores 2 is not less than 1.
Example 2
The second aspect of the present invention provides a method for exploiting an offshore shale oil and a low-permeability reservoir, which is based on the system for exploiting an offshore shale oil and a low-permeability reservoir in embodiment 1, specifically, the main well electric control on-off valve 65 and the branch oil production well electric control on-off valve 66 are alternately opened or closed.
The main well bore electric control switch valve 65 and the branch oil extraction well bore electric control switch valve 66 are alternately opened or closed, and specifically comprise the following steps:
s1: and at the moment, the formation crude oil in the control area of the main well 1 flows into the well bore through the main well hydraulic fracturing cracks 11, and the formation in the fracturing modification area controlled by the branch oil extraction well 2 enters a seepage storage stage.
S2: when the oil production yield of the main well 1 is lower than the set yield, the electric control on-off valve 65 for controlling the oil production of the main well is closed, the electric control on-off valve 66 for controlling the oil production of the branch well is opened, at this time, the main well 1 control area enters a seepage storage stage, and the crude oil in the stratum of the fracturing modification area controlled by the branch oil production well 2 flows into the well through the hydraulic fracturing cracks 21 of the oil production branch well.
S3: when the yield of the branch oil extraction well bore 2 is lower than the set yield, closing the branch oil extraction well bore electric control switch valve 66 and opening the main well bore electric control switch valve 65;
s4: s1 to S3 are repeated continuously to complete the development.
According to the invention, fracturing transformation and intermittent production of multiple wellbores are carried out in a single wellbore, so that the single-well control area is increased, daily oil production and accumulated oil production of the single well are improved, and the economic benefit of the single well of the offshore oilfield is improved. The invention can realize the setting function by using two packers and two electric control switch valves, and has simple structure, convenient implementation and lower cost.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (9)
1. The offshore shale oil and low-permeability reservoir exploitation system comprises an oil production pipe column assembly, wherein the oil production pipe column assembly comprises an oil production pipe column, and is characterized by further comprising a main well bore, a branch oil production well bore and a directional perforation hole, wherein the main well bore is connected with the branch oil production well bore through the directional perforation hole; the oil production pipe column is provided with a main well hole control tool and a branch well hole control tool, the main well hole control tool is arranged at the main well hole, and the main well hole control tool is configured to communicate or seal the oil production pipe column and an annular flow passage; the branch wellbore control tool is disposed at the branch production wellbore, the branch wellbore control tool configured to open or close the production string.
2. The offshore shale oil and low permeability reservoir production system of claim 1, wherein the main wellbore control tool comprises a main wellbore packer and a main wellbore electrically controlled on-off valve, the main wellbore packer and the main wellbore electrically controlled on-off valve are disposed at a bottom of the production string assembly, and the main wellbore packer is disposed above the main wellbore electrically controlled on-off valve, the main wellbore packer is configured to seal the annulus flow passage, and the main wellbore electrically controlled on-off valve is configured to communicate or seal the production string with the annulus flow passage.
3. The offshore shale oil and low permeability reservoir production system of claim 2, wherein the lateral production wellbore control tool comprises a lateral production wellbore packer and a lateral production wellbore electrically controlled on/off valve located at the lateral production wellbore, and the lateral production wellbore packer is disposed below the lateral production wellbore electrically controlled on/off valve, the lateral production wellbore packer being configured to seal the annulus flow passage, the lateral production wellbore electrically controlled on/off valve being configured to open or close the production string.
4. The offshore shale oil and low-permeability reservoir exploitation system according to claim 3, wherein the oil production string assembly further comprises a power cable, an electric pump unit, a hydraulic control pipeline, a ground control safety valve and a production sliding sleeve, the electric pump unit is arranged on the oil production string through a Y joint, the ground control safety valve is arranged on the oil production string and connected with the hydraulic control pipeline, the power cable is respectively connected with the electric pump unit, the production sliding sleeve is arranged at the bottom of the oil production string, and the main well packer, the main well electric control switching valve, the branch oil production well electric control switching valve and the branch oil production well packer are sequentially arranged on the oil production string below the production sliding sleeve.
5. The offshore shale oil and low permeability reservoir production system of any of claims 1-4, wherein the number of branch production wellbores is not less than 1.
6. An offshore shale oil and low permeability reservoir exploitation method, characterized in that based on the offshore shale oil and low permeability reservoir exploitation system as claimed in any one of claims 1 to 5, the method comprises alternately opening or closing a main well electric control on-off valve and a branch oil extraction well electric control on-off valve.
7. The method for exploiting the offshore shale oil and the low-permeability reservoir according to claim 6, wherein the condition that the main well electric control on-off valve is opened is that the main well oil production yield is not lower than a set yield.
8. The method of exploiting an offshore shale oil and low permeability reservoir according to claim 7, wherein the condition that the electrically controlled on-off valve of the branch production well is closed is that the production yield of the branch production well is lower than a set yield.
9. The method for exploiting the offshore shale oil and the low-permeability reservoir according to claim 8, wherein the specific steps of alternately opening or closing the main well electric control switching valve and the branch oil extraction well electric control switching valve are as follows:
opening and controlling a main well electric control switch valve, and closing an electric control switch valve of a branch oil extraction well, wherein at the moment, stratum crude oil in a main well control area flows into a well shaft through a main well hydraulic fracturing crack, and stratum in a fracturing modification area controlled by the branch oil extraction well enters a seepage storage stage;
when the production yield of the main well oil extraction is lower than the set yield, closing an electric control switch valve for controlling the main well oil extraction and opening an electric control switch valve for controlling the branch well oil extraction, wherein at the moment, the main well control area enters a seepage storage stage, and the stratum crude oil in the fracturing modification area controlled by the branch oil extraction well flows into the well through hydraulic fracturing cracks of the oil extraction branch well;
when the yield of the branch oil extraction well bores is lower than the set yield, closing the electric control on-off valve of the branch oil extraction well bores and opening the electric control on-off valve of the main well bores;
the main well electric control switch valve and the branch oil extraction well electric control switch valve in the steps are repeatedly opened or closed alternately, so that development is completed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311751905.8A CN117684919A (en) | 2023-12-19 | 2023-12-19 | Marine shale oil and low-permeability reservoir exploitation system and exploitation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311751905.8A CN117684919A (en) | 2023-12-19 | 2023-12-19 | Marine shale oil and low-permeability reservoir exploitation system and exploitation method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117684919A true CN117684919A (en) | 2024-03-12 |
Family
ID=90136858
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311751905.8A Pending CN117684919A (en) | 2023-12-19 | 2023-12-19 | Marine shale oil and low-permeability reservoir exploitation system and exploitation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117684919A (en) |
-
2023
- 2023-12-19 CN CN202311751905.8A patent/CN117684919A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106194131B (en) | It is spaced CO between multistage fracturing horizontal well seam2Oil flooding method | |
| CN101566053B (en) | System and method to facilitate treatment and production in wellbore | |
| US9127544B2 (en) | Fluid injection in light tight oil reservoirs | |
| US8418768B2 (en) | Bypass gaslift system, apparatus, and method for producing a multiple zones well | |
| EP2715039A2 (en) | Wellbore junction completion with fluid loss control | |
| CN102410009B (en) | Controlled-valve placed well-cementing staged-fracturing well-completion string and hydraulically-controlled switch string | |
| RU2594235C2 (en) | Method of simultaneous separate operation of multi layer deposit and device for realizing said method | |
| GB2471354A (en) | Wellbore junction | |
| CN102906365B (en) | Pressure controlled wellbore structure and operating system and can be used for the method for hydrocarbon operation, storage and solution exploitation | |
| CN111946300B (en) | Same-well same-layer multi-lateral self-injection and production underground fluid separation self-driving well and production method | |
| RU2260681C2 (en) | Oil and gas deposit development method | |
| RU2770229C1 (en) | Smart system for completing multi-barrel borehole with wired high-tech well in main borehole and with wireless electronic unit for flow control in side borehole | |
| CN117684919A (en) | Marine shale oil and low-permeability reservoir exploitation system and exploitation method | |
| CN111963119B (en) | Underground fluid separation self-driven well for same-well multilayer self-injection and production method | |
| CN108194050A (en) | A kind of underground sliding sleeve open method and device | |
| US11306569B2 (en) | Electronic control for simultaneous injection and production | |
| CN113404468A (en) | Novel gas-liquid separate production pipe column for underground drainage and gas production of sulfur-containing gas well | |
| CA3026636C (en) | System and method for enhanced oil recovery | |
| CN111963120B (en) | Downhole fluid separation self-driving well for same-well and same-layer self injection and production method | |
| CN111946299B (en) | Downhole fluid separation self-driving well for same-well and same-layer self injection and production method | |
| RU2815898C1 (en) | Method for construction and operation of well with extraction of part of liner | |
| RU2713819C1 (en) | Bottom-hole fluid flow switch in well for various operating modes (embodiments) | |
| RU2775628C1 (en) | Method for completing a horizontal sidetrack borehole followed by multi-stage hydraulic fracturing | |
| US11434704B2 (en) | Alternate path for borehole junction | |
| CN220203872U (en) | Horizontal well layered exploitation tubular column |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |