A method to improve the positioning accuracy of LZ continuous whipstock

Abstract

The present invention discloses a method for improving the positioning accuracy of a LZ continuous whipstock, comprising the following steps: step one, setting an artificial hole bottom at a position where directional drilling is to be prepared; step two, using a gyro inclinometer to measure the curvature of the borehole; step three, placing the LZ continuous whipstock according to the measurement result of step two, simulating the actual top angle and azimuth of the hole bottom drilling tool at this time, requiring the continuous whipstock slider generatrix to be in a straight line with the lowest point of the drill bit; step four, using the drill bit surface at the bottom of the LZ continuous whipstock as an axial horizontal projection, using the drill bit and the ground contact point as a construction coordinate system, and constructing a whipstock range quadrant; step five, according to directional requirements, rotating the drill tool (axial rotation) so that the continuous whipstock generatrix is ​​in the corresponding whipstock quadrant. The present invention effectively improves the positioning accuracy of the LZ continuous whipstock, achieves the expected effect of directional drilling of the tool, avoids the scrapping of drilling holes, avoids the waste of resources and environmental pollution caused by re-construction, and improves the efficiency of prospecting and prospecting.

Description

Technical Field

[0001] The invention relates to the technical field of solid mineral drilling directional construction technology, and in particular to a method for improving the positioning accuracy of an LZ continuous whipstock. Background Art

[0002] At present, there are three types of tools in the directional construction of solid mineral drilling, namely eccentric wedges, continuous whipstocks, and screw drills. Among them, eccentric wedges are generally used in shallow drilling because they need to change diameters for construction, are not accurate in orientation, and leave behind troubles; screw drills have high requirements for the sealing of mud pumps and drill pipes due to their working principle, and their deflection efficiency in medium-hard and above formations is too low, so they are generally less used in solid minerals. Compared with these two tools, the continuous whipstock has the characteristics of simple directional construction and high deflection efficiency. However, the orientation of the continuous whipstock often adopts a calculation method, which cannot eliminate human errors, resulting in unsatisfactory actual deflection effects, or even counterproductive effects, which causes many boreholes to be scrapped, resulting in a large amount of economic losses, and delaying the exploration and development of minerals. The proposed method can not only promote the application of LZ continuous whipstocks, but also reduce the scrapping of boreholes, avoid the waste of resources for re-drilling, and effectively avoid or reduce the huge losses in resource development caused by prospecting. Summary of the invention

[0003] The purpose of the present invention is to propose a method for improving the positioning accuracy of the LZ continuous whipstock based on the summary of the previous successes and failures in the use of the LZ continuous whipstock. By dividing the whipstock range into quadrants, the angle between the guide shoe of the direction finder and the probe tube is determined by ground simulation orientation and inversion, and human and instrument errors are eliminated as much as possible. Afterwards, the continuous whipstock is lowered, and the ground display is used as a reference. By removing invalid marks and adopting the normal distribution principle, the orientation error is reduced to ensure the installation position of the continuous whipstock slider busbar. Thus, a method for improving the positioning accuracy of the LZ continuous whipstock is provided, which solves the technical problems existing in the above-mentioned background technology.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A method for improving the positioning accuracy of a LZ continuous whipstock includes the following steps:

[0006] Step 1: Set the bottom of the artificial hole at the location where directional drilling is to be carried out;

[0007] Step 2: Using a gyro inclinometer to measure the curvature of the borehole;

[0008] Step 3: Place the LZ continuous whipstock according to the measurement results of step 2 to simulate the actual top angle and azimuth of the bottom hole drill bit at this time, and require that the generatrix of the continuous whipstock slider and the lowest point of the drill bit are in a straight line;

[0009] Step 4: Take the drill bit surface at the bottom of the LZ continuous whipstock as the axial horizontal projection, build a coordinate system with the contact point between the drill bit and the ground as the origin, and build the whipstock range quadrant;

[0010] Step 5: According to the directional requirements, the drill bit is rotated in an axial rotation mode (axial rotation) so that the generatrix of the continuous whipstock slider is in the corresponding whipstock quadrant;

[0011] Step 6: Lower the directional instrument and adjust the angle b between the directional guide shoe mark and the probe tube busbar according to step 5;

[0012] Step 7: Use the ground display of the directional instrument to invert the position of the continuous whipstock slider generatrix a. Adjust the angle b between the directional guide shoe mark and the probe tube generatrix again;

[0013] Step 8: After lowering the LZ continuous whipstock into the hole to the predetermined position, lower the directional tool and make a reference mark somewhere on the drill pipe;

[0014] Step 9: Rotate the drill pipe, and confirm the ground marks L1 and L2 by the ground display of the directional instrument showing short zero;

[0015] Step 10. Repeat step 9 to repeatedly determine the ground marks L1', L1" ..., L2', L2" ..., and the two groups of marks belong to normal distribution; take the middle of the peak of the L1 series and the peak of the L2 series as the lowering position of the continuous whipstock.

[0016] Furthermore, in step 1, the following setting requirements are made for the bottom of the artificial hole: using cement of P.O42.5 grade or above, with a water-cement ratio of 0.4-0.5, solidifying for more than 72 hours, and a cement plug length of 10-15 meters.

[0017] Furthermore, the measurement requirements in step 2 are as follows: measurement is performed from the bottom of the artificial hole to 20 meters above the bottom of the hole at a spacing of 1 meter per point.

[0018] Furthermore, the placement requirements of the LZ continuous whipstock in step three are as follows: the continuous whipstock is fixed in position but can rotate axially.

[0019] Furthermore, the deflection range quadrants in step 4 are divided as follows: based on the relative position of the continuous deflector slider generatrix a at the lowest point A on the bottom surface of the drill bit, the deflection range quadrants are divided into 8 deflection ranges and 4 key points:

[0020] When a is at point A, the directional drilling effect is that the azimuth angle remains unchanged, but the vertex angle increases;

[0021] a is between AB, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the vertex angle change rate is greater than the azimuth angle change rate;

[0022] When a is at point B, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle;

[0023] a is between BC, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the vertex angle change rate is smaller than the azimuth angle change rate;

[0024] When a is at point C, the directional drilling effect is that the azimuth angle decreases and the top angle remains unchanged;

[0025] a is between CD, the directional drilling effect is that the top angle decreases, the azimuth angle decreases, and the rate of change of the top angle is less than the rate of change of the azimuth angle;

[0026] When a is at point D, the directional drilling effect is that the vertex angle decreases, the azimuth angle decreases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle;

[0027] a is between DE, the directional drilling effect is that the top angle decreases, the azimuth angle decreases, and the rate of change of the top angle is greater than the rate of change of the azimuth angle;

[0028] When a is at point E, the directional drilling effect is that the azimuth angle remains unchanged and the top angle decreases;

[0029] a is between EF and EF, the directional drilling effect is that the top angle decreases, the azimuth angle increases, and the rate of change of the top angle is greater than the rate of change of the azimuth angle;

[0030] When a is at point F, the directional drilling effect is that the vertex angle decreases, the azimuth angle increases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle;

[0031] a is between FG, the directional drilling effect is that the top angle decreases, the azimuth angle increases, and the rate of change of the top angle is less than the rate of change of the azimuth angle;

[0032] When a is at point G, the directional drilling effect is that the azimuth angle increases and the vertex angle remains unchanged;

[0033] a is between GH, the directional drilling effect is that the vertex angle increases, the azimuth angle increases, and the vertex angle change rate is smaller than the azimuth angle change rate;

[0034] When a is at point H, the directional drilling effect is that the vertex angle increases, the azimuth angle increases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle;

[0035] a is between HA, and the directional drilling effect is that the top angle increases, the azimuth angle increases, and the rate of change of the top angle is greater than the rate of change of the azimuth angle.

[0036] Furthermore, the requirement for adjusting the angle b between the directional guide shoe mark and the probe tube busbar in step six is: repeat step five multiple times, fine-tune the angle b, and eliminate the instrument error caused by the gap between the positioning key and the directional guide shoe.

[0037] Furthermore, the requirement for adjusting the angle b between the directional guide shoe mark and the probe tube busbar in step seven is as follows: based on the display inversion adjustment of the short zero on the ground display of the direction finder, ensure that within the 15° range of the short zero display, the busbar a of the continuous whipstock slider is always in the middle of the whipstocking range required for orientation or evenly spans the key points.

[0038] Furthermore, the reference mark requirement in step eight is: draw a plumb line of 1 to 2 meters on the drill pipe in a bright color.

[0039] Furthermore, in step nine, the drill pipe rotation is required to be no more than 6° per second; the method for determining the ground mark is: when the ground display of the orienteering instrument begins to show short zero, a mark is made from the drill pipe reference mark to the ground; when the ground display of the orienteering instrument ends the short zero, another mark is made from the drill pipe reference mark to the ground in another color; the angle of the two marks is 15°±5° for a valid mark.

[0040] Furthermore, the requirement for the normal distribution in step 10 is: there are no less than 10 groups of valid marks, and the maximum phase difference of the marks in the L1 or L2 series does not exceed 10°.

[0041] Compared with the prior art, the beneficial technical effects of the present invention are:

[0042] The present invention divides quadrants according to the deflection range to preliminarily determine the placement range of the continuous whipstock; through multiple ground simulations and inversions and the normal distribution principle to determine the effective position, to ensure that the continuous whipstock is in the most advantageous position in the installation quadrant, further accurately determine the installation position of the continuous whipstock slider busbar, reduce the subjective error of human adjustment and the objective error of the instrument, thereby improving the positioning accuracy of the LZ continuous whipstock, achieving the directional drilling effect of the tool, avoiding the scrapping of boreholes, avoiding the waste of resources and environmental pollution caused by re-construction, improving the efficiency of mineral exploration, and supplementing the directional drilling technology needs for deep detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described below in conjunction with the accompanying drawings.

[0044] Figure 1 It is a schematic diagram of the bottom of the artificial hole in step 1;

[0045] Figure 2 This is a schematic diagram of the placement of the LZ continuous whipstock in step three;

[0046] Figure 3 This is a schematic diagram of the quadrant division of the deflection range in step 4;

[0047] Figure 4 This is a schematic diagram of the value of the lowering position of the LZ continuous whipstock in step ten;

[0048] Description of the accompanying drawings: 1. Cement plug. DETAILED DESCRIPTION

[0049] like Figure 1-Figure 3 As shown, a method for improving the positioning accuracy of the LZ continuous whipstock comprises the following steps:

[0050] Step 1: Set up the bottom of the artificial hole at the location where directional drilling is to be carried out, such as Figure 1 As shown, the following setting requirements are made for the bottom of the artificial hole: use cement of P.O42.5 grade or above, water-cement ratio of 0.4-0.5, solidify for more than 72 hours, and the length of the cement plug 1 is required to be 10-15 meters. Figure 1 The old hole refers to the drill hole that needs directional deviation, and the new hole refers to the drill hole after directional drilling is implemented.

[0051] Step 2: Use a gyro inclinometer to measure the curvature of the borehole. The measurement should be carried out from the bottom of the artificial hole to 20 meters above the bottom of the hole at a spacing of 1 meter per point.

[0052] Step 3: Place the LZ continuous whipstock according to the measurement results of step 2 to simulate the actual top angle and azimuth of the bottom hole drill bit at this time. Figure 2 As shown, the continuous whipstock slider generatrix is ​​required to be in a straight line with the lowest point of the drill bit; and the placement of the LZ continuous whipstock requires that the continuous whipstock is fixed in position but can rotate axially.

[0053] Step 4: Take the drill bit surface at the bottom of the LZ continuous whipstock as the axial horizontal projection, build a coordinate system with the contact point between the drill bit and the ground as the origin, and build the whipstock range quadrant. Figure 3 As shown in FIG. 1 , the deflection range quadrant is divided as follows: based on the relative position of the continuous deflector slider generatrix a at the lowest point A on the bottom surface of the drill bit, the deflection range quadrant is divided into 8 deflection ranges and 4 key points:

[0054] When a is at point A, the directional drilling effect is that the azimuth angle remains unchanged, but the vertex angle increases;

[0055] a is between AB, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the vertex angle change rate is greater than the azimuth angle change rate;

[0056] When a is at point B, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle;

[0057] a is between BC, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the vertex angle change rate is smaller than the azimuth angle change rate;

[0058] When a is at point C, the directional drilling effect is that the azimuth angle decreases and the top angle remains unchanged;

[0059] a is between CD, the directional drilling effect is that the top angle decreases, the azimuth angle decreases, and the rate of change of the top angle is less than the rate of change of the azimuth angle;

[0060] When a is at point D, the directional drilling effect is that the vertex angle decreases, the azimuth angle decreases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle;

[0061] a is between DE, the directional drilling effect is that the top angle decreases, the azimuth angle decreases, and the rate of change of the top angle is greater than the rate of change of the azimuth angle;

[0062] When a is at point E, the directional drilling effect is that the azimuth angle remains unchanged and the top angle decreases;

[0063] a is between EF and EF, the directional drilling effect is that the top angle decreases, the azimuth angle increases, and the rate of change of the top angle is greater than the rate of change of the azimuth angle;

[0064] When a is at point F, the directional drilling effect is that the vertex angle decreases, the azimuth angle increases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle;

[0065] a is between FG, the directional drilling effect is that the top angle decreases, the azimuth angle increases, and the rate of change of the top angle is less than the rate of change of the azimuth angle;

[0066] When a is at point G, the directional drilling effect is that the azimuth angle increases and the vertex angle remains unchanged;

[0067] a is between GH, the directional drilling effect is that the vertex angle increases, the azimuth angle increases, and the vertex angle change rate is smaller than the azimuth angle change rate;

[0068] When a is at point H, the directional drilling effect is that the vertex angle increases, the azimuth angle increases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle;

[0069] a is between HA, and the directional drilling effect is that the top angle increases, the azimuth angle increases, and the rate of change of the top angle is greater than the rate of change of the azimuth angle.

[0070] Step 5: According to the directional requirements, rotate the drill bit in an axial rotation mode so that the generatrix of the continuous whipstock slider is in the corresponding whipstock quadrant.

[0071] Step six, lower the directional instrument and adjust the angle b between the directional guide shoe mark and the probe tube busbar according to step five. The requirement for adjusting the angle b between the directional guide shoe mark and the probe tube busbar in this step is: it is necessary to repeat step five several times and fine-tune the angle b to eliminate the instrument error caused by the gap between the positioning key and the directional guide shoe.

[0072] Step 7: Invert the position of the continuous whipstock slider busbar a with the ground display of the directional instrument. Adjust the angle b between the directional guide shoe mark and the probe tube busbar again; in this step, adjust the angle b between the directional guide shoe mark and the probe tube busbar: according to the display inversion adjustment of the short zero of the ground display of the directional instrument, ensure that the continuous whipstock slider busbar a is always in the middle of the deflection range required by the orientation or evenly crosses the key points within the 15° range of the short zero display.

[0073] Step 8. After lowering the LZ continuous whipstock into the predetermined position in the hole, lower the directional control instrument and make a reference mark somewhere on the drill pipe. The reference mark requirement is: draw a plumb line of 1 to 2 meters on the drill pipe in a bright color.

[0074] Step nine, rotate the drill pipe, and determine the ground marks L1 and L2 through the short zero displayed by the ground display of the directional control instrument. In this step, the drill pipe rotation requirement is not more than 6° per second. The method for determining the ground mark is: when the ground display of the directional control instrument begins to display short zero, make a mark from the drill pipe reference mark to the ground; when the ground display of the directional control instrument ends short zero, make another mark from the drill pipe reference mark to the ground in another color; the angle of the two marks is 15°±5° for a valid mark.

[0075] Step 10: Repeat step 9 to determine the ground marks L1', L1" ..., L2', L2" ... for multiple times, and the two sets of marks belong to normal distribution; Figure 4 As shown, the middle of the peak of the L1 series and the peak of the L2 series is taken as the lowering position of the LZ continuous whipstock. The requirements for normal distribution in this step are: there are no less than 10 groups of valid marks, and the maximum difference between the marks in the L1 or L2 series does not exceed 10°.

[0076] The present invention first divides the deflection range into quadrants, preliminarily determines the placement orientation of the continuous whipstock, uses the ground simulation orientation method to determine that the short zero area of ​​the orientation instrument is on both sides of the most favorable position of the installation quadrant, determines the angle between the orientation instrument guide shoe and the probe, and then determines the placement angle of the continuous whipstock in the hole based on this angle; through ground simulation and inversion, the effective position is determined by using the normal distribution principle, and the installation position of the continuous whipstock slider busbar is further accurately determined, reducing the subjective error of manual adjustment and the objective error of the instrument. Thereby improving the positioning accuracy of the LZ continuous whipstock, achieving the directional drilling effect of the tool, avoiding the scrapping of the borehole, avoiding the waste of resources and environmental pollution caused by re-construction, improving the efficiency of prospecting and prospecting, and providing a method for improving the positioning accuracy of the LZ continuous whipstock.

[0077] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for improving the positioning accuracy of a LZ continuous whipstock, characterized in that: The steps include: Step 1: Set the bottom of the artificial hole at the location where directional drilling is to be carried out; Step 2: Using a gyro inclinometer to measure the curvature of the borehole; Step 3: Place the LZ continuous whipstock according to the measurement results of step 2 to simulate the actual top angle and azimuth of the bottom hole drill bit at this time, and require that the generatrix of the continuous whipstock slider and the lowest point of the drill bit are in a straight line; Step 4: Take the drill bit surface at the bottom of the LZ continuous whipstock as the axial horizontal projection, build a coordinate system with the contact point between the drill bit and the ground as the origin, and build the whipstock range quadrant; The deflection range quadrants in step 4 are divided as follows: based on the relative position of the continuous deflector slider generatrix a at the lowest point A on the bottom surface of the drill bit, the deflection range quadrants are divided into 8 deflection ranges and 4 key points: When a is at point A, the directional drilling effect is that the azimuth angle remains unchanged, but the vertex angle increases; a is between AB, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the vertex angle change rate is greater than the azimuth angle change rate; When a is at point B, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle; a is between BC, the directional drilling effect is that the vertex angle increases, the azimuth angle decreases, and the vertex angle change rate is smaller than the azimuth angle change rate; When a is at point C, the directional drilling effect is that the azimuth angle decreases and the top angle remains unchanged; a is between CD, the directional drilling effect is that the top angle decreases, the azimuth angle decreases, and the rate of change of the top angle is less than the rate of change of the azimuth angle; When a is at point D, the directional drilling effect is that the vertex angle decreases, the azimuth angle decreases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle; a is between DE, the directional drilling effect is that the top angle decreases, the azimuth angle decreases, and the rate of change of the top angle is greater than the rate of change of the azimuth angle; When a is at point E, the directional drilling effect is that the azimuth angle remains unchanged and the top angle decreases; a is between EF and EF, the directional drilling effect is that the top angle decreases, the azimuth angle increases, and the rate of change of the top angle is greater than the rate of change of the azimuth angle; When a is at point F, the directional drilling effect is that the vertex angle decreases, the azimuth angle increases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle; a is between FG, the directional drilling effect is that the top angle decreases, the azimuth angle increases, and the rate of change of the top angle is less than the rate of change of the azimuth angle; When a is at point G, the directional drilling effect is that the azimuth angle increases and the vertex angle remains unchanged; a is between GH, the directional drilling effect is that the vertex angle increases, the azimuth angle increases, and the vertex angle change rate is smaller than the azimuth angle change rate; When a is at point H, the directional drilling effect is that the vertex angle increases, the azimuth angle increases, and the rate of change of the vertex angle is equal to the rate of change of the azimuth angle; a is between HA, the directional drilling effect is that the vertex angle increases, the azimuth angle increases, and the vertex angle change rate is greater than the azimuth angle change rate; Step 5: According to the directional requirements, the drilling tool is rotated in the form of axis rotation so that the generatrix of the continuous whipstock slider is in the corresponding whipstock quadrant; Step 6: Lower the directional instrument and adjust the angle b between the directional guide shoe mark and the probe tube busbar according to step 5; Step 7: Invert the position of the continuous whipstock slider busbar a using the ground display of the directional instrument; adjust the angle b between the directional guide shoe mark and the probe tube busbar again; The requirement for adjusting the angle b between the directional guide shoe mark and the probe tube busbar in step 7 is: according to the display inversion adjustment of the short zero of the ground display of the directional instrument, ensure that within the range of 15° of the short zero display, the busbar a of the continuous whipstock slider is always in the middle of the deflection range required by the orientation or evenly spans the key points; Step 8: After lowering the LZ continuous whipstock into the hole to the predetermined position, lower the directional tool and make a reference mark somewhere on the drill pipe; Step 9: Rotate the drill pipe, and confirm the ground marks L1 and L2 by the ground display of the directional instrument showing short zero; Step 10. Repeat step 9 to repeatedly determine the ground marks L1', L1" ..., L2', L2" ..., and the two groups of marks belong to normal distribution; take the middle of the peak of the L1 series and the peak of the L2 series as the lowering position of the continuous whipstock.

2. The method for improving the positioning accuracy of the LZ continuous whipstock according to claim 1, characterized in that: In step 1, the following setting requirements are made for the bottom of the artificial hole: using cement of P.O42.5 grade or above, with a water-cement ratio of 0.4-0.5, solidifying for more than 72 hours, and a cement plug length of 10-15 meters.

3. The method for improving the positioning accuracy of the LZ continuous whipstock according to claim 1, characterized in that: The measurement requirements in step 2 are as follows: measurement is performed from the bottom of the artificial hole to 20 meters above the bottom of the hole at a spacing of 1 meter per point.

4. The method for improving the positioning accuracy of the LZ continuous whipstock according to claim 1, characterized in that: The placement requirements of the LZ continuous whipstock in step three are as follows: the continuous whipstock is fixed in position but can rotate axially.

5. The method for improving the positioning accuracy of the LZ continuous whipstock according to claim 1, characterized in that: Requirements for adjusting the angle b between the directional guide shoe mark and the probe tube busbar in step six: Repeat step five several times, fine-tune the angle b, and eliminate the instrument error caused by the gap between the positioning key and the directional guide shoe.

6. The method for improving the positioning accuracy of the LZ continuous whipstock according to claim 1, characterized in that: The reference mark requirement in step eight is: draw a plumb line of 1 to 2 meters on the drill pipe in a bright color.

7. The method for improving the positioning accuracy of the LZ continuous whipstock according to claim 1, characterized in that: The drill pipe rotation requirement in step nine is no more than 6° per second; the method for determining the ground mark is: when the ground display of the orienteering instrument starts to show short zero, a mark is made from the drill pipe reference mark to the ground; when the ground display of the orienteering instrument ends the short zero, another mark is made from the drill pipe reference mark to the ground in another color; the angle of the two marks is 15°±5° for a valid mark.

8. The method for improving the positioning accuracy of the LZ continuous whipstock according to claim 1, characterized in that: The requirements for the normal distribution in step 10 are: there are no less than 10 groups of valid marks, and the maximum phase difference of the marks in the L1 or L2 series does not exceed 10°.

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