CN115434636A - Well deviation adjustment method for horizontal wells before landing based on double constraints of marker layers and included angles - Google Patents

Abstract

The invention relates to the technical field of shale gas exploration and development, in particular to a method for adjusting the well inclination of a horizontal well before landing based on double constraints of marker layers and included angles. Obtain the data of standard wells, drilled horizontal wells, and horizontal wells to be drilled; establish the corresponding relationship between standard wells and drilled horizontal wells; obtain model empirical coefficients by marking the corresponding standard well spacing A target point thickness h and included angle γ; use The regression equation establishes the marker layer and included angle chart of the standard well; calculates the well deviation that should be adjusted from the horizontal well to be drilled to the corresponding marker layer; controls the trajectory of the horizontal well to be drilled before landing according to the calculation results; enters the A target when the horizontal well to be drilled lands Posture control. It has strong operability, is easy to popularize and apply on site, achieves the purpose of controlling smooth and precise landing before landing, and meets the needs of fast, safe and efficient drilling for multi-layer three-dimensional development of gas fields.

Description

Well deviation adjustment method for horizontal wells before landing based on double constraints of marker layers and included angles

technical field

The invention relates to the technical field of shale gas exploration and development, in particular to a method for adjusting the well inclination of a horizontal well before landing based on double constraints of marker layers and included angles.

Background technique

Accurate landing is one of the key technologies for horizontal well geosteering. The traditional horizontal well deviation adjustment trajectory method before landing mainly uses the equal thickness method to dynamically predict the vertical depth of the A target point and adjust it in real time. There are many parameters while drilling and the calculation process is complicated. Especially when the trajectory azimuth changes before landing, the calculation error of the apparent dip angle of the formation is prone to be too large, which will affect the trajectory control before landing, landing attitude and trajectory smoothness, and then affect the follow-up level. section of construction.

CN108316859A discloses a shale gas horizontal well drilling-while-drilling formation trajectory control method before landing. The core is to provide an empirical parameter matching the vertical depth of the marker layer, the vertical thickness and displacement, and the build-up rate. However, for the angle between the trajectory and the formation A quick calculation method for the adjustment is not mentioned.

Therefore, for formations with similar intervals before landing and relatively stable occurrences before landing in the well area, it is urgent to establish a well-deviation analysis method based on marker layers and included angle constraints, which is highly operable and easy to popularize and apply in the field. The simple calculation method for section adjustment achieves the goal of controlling smooth and precise landing before landing, and meets the needs of fast, safe and efficient drilling for multi-layer three-dimensional development of gas fields.

Contents of the invention

The object of the present invention is to aim at the defects of the prior art, to provide a method for adjusting the well deviation before landing of a horizontal well based on the double constraints of the marker layer and the included angle, which has strong operability, is easy to be popularized and applied on site, and achieves smooth and smooth trajectory control before landing. The purpose of precise landing is to meet the needs of fast, safe and efficient drilling for multi-layer three-dimensional development of gas fields.

The present invention is a method for adjusting the well inclination of a horizontal well before landing based on the dual constraints of the marker layer and the included angle, which is characterized in that it includes:

Obtain the data of standard wells, drilled horizontal wells and horizontal wells to be drilled;

Establish the corresponding relationship between standard wells and drilled horizontal wells;

The empirical coefficient of the model is obtained by marking the corresponding standard well spacing A target point thickness h and included angle γ;

Use the regression equation to establish the mark layer and angle chart of the standard well;

Calculate the well deviation that should be adjusted from the horizontal well to be drilled to the corresponding marker layer;

Control the pre-landing trajectory of the horizontal well to be drilled according to the calculation results;

When the horizontal well to be drilled lands, it enters the A target attitude control.

More preferably, the data of said acquisition of standard wells, drilled horizontal wells, and horizontal wells to be drilled includes:

Obtain geological stratification, lithology, natural gamma ray, gas logging, geochemical and elemental data of standard wells;

Obtain the table data of geological stratification, lithology, natural gamma ray, gas logging and well deviation of drilled horizontal wells;

Obtain lithology, natural gamma ray, gas logging, depth while drilling, well deviation and azimuth data of horizontal wells to be drilled.

More preferably, the selection method of the drilled horizontal well comprises:

A representative horizontal well drilled with relatively stable formation occurrence, relatively stable thickness, 250-350m displacement before landing, and an average full-angle change rate of the landing section track less than 15°/100m, and accurate landing was selected as the modeling well.

More preferably, establishing the corresponding relationship between standard wells and drilled horizontal wells includes:

By comparing the strata of standard wells and drilled horizontal wells, identify all marker layers up to S1m from target A, and number the marker layers from top to bottom;

Read the well depth, well inclination and azimuth data from the first marker layer to target point A of the drilled horizontal well;

By comparing the lithology, natural gamma ray and gas logging characteristics of the standard wells with those of the drilled horizontal wells, mark the depth value and well deviation data on the well deviation data table of the drilled horizontal wells to the corresponding standard wells;

The standard well depth corresponding to the label is converted into the thickness h from the target point A, and the well inclination data is converted into the included angle γ, and the included angle γ refers to the included angle between the trajectory line and the formation.

More preferably, the empirical coefficients of the model obtained by marking the corresponding standard well distance target point thickness h and included angle γ include:

By marking the corresponding standard well distance A target thickness h and included angle γ data samples, draw the intersection diagram of included angle γ-distance A target thickness h;

Establish a polynomial regression equation with the thickness h from A target as the independent variable and the included angle γ as the dependent variable;

Obtain the model experience coefficients A, B, C of the model γ=Ah ³ +Bh ² +Ch+2.00.

More preferably, said using the regression equation to establish the marker layer and the included angle chart of the standard well includes:

From top to bottom, draw the charts of standard wells including well depth, natural gamma ray, marker layer, lithology, and included angle items.

More preferably, the calculation of the well deviation that should be adjusted from the horizontal well to be drilled to the corresponding marker layer includes:

According to the formula γ=90-α-β, the angle γ between the trajectory line and the formation is converted into the well deviation that should be adjusted from the horizontal well to be drilled to the corresponding marker layer;

Among them, β is the apparent dip angle of the formation, and α is the well inclination angle.

More preferably, said controlling the pre-landing trajectory of the horizontal well to be drilled according to the calculation results includes:

Using the principle of adjacent similarity, according to the calculation result of the stratum apparent dip angle of the last marker layer, the stratum apparent dip angle of this layer is obtained;

Determine the well deviation according to the included angle, including

The apparent dip angle of the adjacent strata changes during the actual drilling. If the marker layer is pushed back, that is, the next marker layer is not drilled according to the corresponding included angle and well deviation, and the layer can be continued to explore the layer according to the included angle γ calculated on the chart; if the marker layer is advanced , according to the included angle γ calculated on the chart, the well inclination required for the corresponding included angle can be rapidly increased according to the specified build-up rate.

More preferably, when the horizontal well to be drilled lands, the attitude control of entering A target includes:

When landing, determine the included angle according to the thickness of the target frame;

Among them, when the thickness of the target frame is K meters, control the included angle of K degrees to enter the A target frame.

The beneficial effects of the present invention are:

1) The present invention uses the drilled horizontal well with precise landing and smooth trajectory as the modeling well, and provides a reference for the pre-landing trajectory well deviation control method for the horizontal well to be drilled with comparable conditions.

2) The present invention provides fast calculation of the included angle corresponding to any marker layer within S1 meter of the target point A by establishing the marker layer and the included angle chart, and solves the problem of using the equal thickness method to dynamically predict the vertical depth of the target point A and adjust the required drilling while drilling in real time There are many parameters, and the calculation process is complicated and problematic.

3) The included angle is converted into the well inclination that should be adjusted from the horizontal well to be drilled to the corresponding marker layer, so as to avoid the impact of different stratum occurrence changes on the pre-landing trajectory.

4) The present invention controls the trajectory of the horizontal well to be drilled according to the calculated well deviation, eliminating the frequent adjustment of the trajectory due to the large calculation error of the stratum apparent dip angle under the condition of changing azimuth before landing.

Description of drawings

Fig. 1 is a schematic flow chart of the present invention;

Fig. 2 is a graph showing the relationship between the well deviation α, the formation dip angle β, and the angle γ between the trajectory and the formation;

Figure 3 is the intersect diagram of the thickness h from the target point A - the trajectory and the formation angle γ;

Fig. 4 is a chart of the small layer (marker layer) and the included angle of the standard well A in the J work area.

detailed description

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not intended to limit the present application.

In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and/or components, but does not exclude one or more other Presence or addition of features, wholes, steps, operations, elements, components and/or collections thereof.

It should also be understood that the term "and/or" used in the description of the present application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

As used in this specification and the appended claims, the term "if" may be construed, depending on the context, as "when" or "once" or "in response to determining" or "in response to detecting ". Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be construed, depending on the context, to mean "once determined" or "in response to the determination" or "once detected [the described condition or event] ]” or “in response to detection of [described condition or event]”.

In addition, in the description of the specification and appended claims of the present application, the terms "first", "second", "third" and so on are only used to distinguish descriptions, and should not be understood as indicating or implying relative importance.

Reference to "one embodiment" or "some embodiments" or the like in the specification of the present application means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in other embodiments," etc. in various places in this specification are not necessarily All refer to the same embodiment, but mean "one or more but not all embodiments" unless specifically stated otherwise. The terms "including", "comprising", "having" and variations thereof mean "including but not limited to", unless specifically stated otherwise. "Multiple" means "two or more"

Embodiment one

Fig. 1 shows a schematic flow chart of a method for adjusting the well inclination before landing of a horizontal well based on the dual constraints of the marker layer and the angle provided by the preferred embodiment of the present application (Fig. 1 shows the first embodiment of the present application), for For the convenience of description, only the parts related to this embodiment are shown, and the description will be made in conjunction with block J of the Fuling shale gas exploration area, as follows:

Step 1, obtain the data of standard wells, drilled horizontal wells and horizontal wells to be drilled;

Step 2, establishing the corresponding relationship between standard wells and drilled horizontal wells;

Step 3, obtain the model empirical coefficient by marking the corresponding standard well distance target point thickness h and included angle γ;

Step 4, using the regression equation to establish the marker layer and the included angle chart of the standard well;

Step 5, calculating the well deviation that should be adjusted from the horizontal well to be drilled to the corresponding marker layer;

Step 6, controlling the trajectory of the horizontal well to be drilled before landing according to the calculation results;

Step 7, enter A target attitude control when the horizontal well to be drilled lands.

In one embodiment, in step 1, said acquisition of standard wells, drilled horizontal wells, and horizontal wells to be drilled includes:

Obtain data such as geological stratification, lithology, natural gamma ray, gas logging, geochemistry, elements, etc. of standard wells. Standard wells refer to vertical wells and pilot wells that have been drilled in different parts of the structure;

Obtain data such as geological layering, lithology, natural gamma ray, gas logging, and well deviation data tables of drilled horizontal wells; the specific methods are as follows:

Select the horizontal wells that have been drilled in the area, select the change of formation occurrence is less than 5°, the relative error of the thickness within 120m above target point A is less than 10% compared with the standard well, the displacement before landing is 250-350m, and the average full-angle change of the trajectory of the landing section If the rate is lower than 15°/100m, accurately land representative wells as modeling wells. When the displacement changes greatly before landing, another drilled horizontal well can be selected to make the chart according to the same process.

The displacement before landing refers to the coordinate displacement difference; the azimuth should be twisted as far as possible before landing. If it is not turned in place, the azimuth change should be controlled within 10°-20°. If the azimuth exceeds the range, it will affect the calculation result of the apparent inclination of the formation.

The well deviation data table includes data such as well depth, well deviation, azimuth, and coordinate displacement difference.

Obtain data such as lithology, natural gamma ray, gas logging, depth while drilling, well deviation, and azimuth of horizontal wells to be drilled.

In one embodiment, in step 2, establishing the corresponding relationship between standard wells and drilled horizontal wells includes:

Through the comparison of standard wells and drilled horizontal wells, all marker layers that are S1 meters above target point A are identified, and the marker layers are numbered from top to bottom. Among them, the optimal choice of S1 meter is 120m;

Read the well depth, well inclination and azimuth data from the first marker layer to target point A of the drilled horizontal well. The reading interval is based on the interval of the well deviation data table, and the interval is controlled within 10m;

By comparing the lithology, natural gamma ray and gas logging characteristics of the standard wells with those of the drilled horizontal wells, mark the depth value and well deviation data on the well deviation data table of the drilled horizontal wells to the corresponding standard wells;

The standard well depth corresponding to the label is converted into the thickness h from the target point A, and the well inclination data is converted into the included angle γ, and the included angle γ refers to the included angle between the trajectory line and the formation.

The standard well depth value corresponding to the label is converted into the thickness h from the target point A as follows:

The conversion is carried out according to the following formula, which is:

Thickness h from target point A = depth of target point A in the standard well - depth corresponding to the marker layer of the standard well

In one embodiment, in step 3, the model experience coefficient obtained by marking the corresponding standard well spacing A target point thickness h and included angle γ includes:

By marking the corresponding standard well distance target thickness h and included angle γ data samples, draw the intersection diagram of included angle γ-target thickness h from A, as shown in Figure 3;

Establish a polynomial regression equation with the thickness h from A target as the independent variable and the included angle γ as the dependent variable;

Set the intercept on the Y axis to 2.00, select the polynomial order to be 3, and obtain the model empirical coefficients A, B, and C of the model γ=Ah ³ +Bh ² +Ch+2.00. When the intercept on the Y axis is 2.00, that is, the included angle of 2.00 degrees is the most suitable for entering the A target. The best fit is when the polynomial order is selected as 3.

The dimension of model coefficient A is °/m ³ , the dimension B is °/m ² , and the dimension C is °/m.

Taking the standard well A in block J of the Fuling shale gas field as an example, using the corresponding relationship between the standard well A and the drilled horizontal well B, the model coefficients obtained are A=0.000028, B=-0.008321, C=0.971720, R ² = 0.984765.

In one embodiment, in step 4, the establishment of the marker layer and the included angle chart of the standard well using the regression equation includes:

From top to bottom, draw the charts of standard wells including well depth, natural gamma ray, marker layer, lithology, and included angle items.

Taking the standard well A in Block J of Fuling shale gas area as an example, use ResForm, Kaben, DGR3000 and other software to draw the charts including well depth, natural gamma ray, marker layer, lithology, included angle and other items from top to bottom ,As shown in Figure 4.

In one embodiment, in step 5, the calculation of the well deviation that should be adjusted from the horizontal well to be drilled to the corresponding marker layer includes:

As shown in Figure 2, according to the formula γ=90-α-β, the angle γ between the trajectory line and the formation is converted into the well deviation that should be adjusted from the horizontal well to be drilled to the corresponding marker layer;

Among them, β is the apparent dip angle of the formation, where downdip is + and updip is -, unit, °; α is inclination angle, unit, °.

In one embodiment, in step 6, said controlling the pre-landing trajectory of the horizontal well to be drilled according to the calculation results includes:

Using the principle of adjacent similarity, according to the calculation result of the stratum apparent dip angle of the last marker layer, the stratum apparent dip angle of this layer is obtained;

Determine the well deviation according to the included angle, including

The apparent dip angle of the adjacent strata changes during the actual drilling. If the marker layer is pushed back, that is, the next marker layer is not drilled according to the corresponding included angle and well deviation, and the layer can be continued to explore the layer according to the included angle γ calculated on the chart; if the marker layer is advanced , according to the included angle γ calculated on the chart, the well inclination required for the corresponding included angle can be rapidly increased according to the specified build-up rate.

In one embodiment, in step 7, the attitude control of entering target A when the horizontal well to be drilled lands includes:

When landing, determine the included angle according to the thickness of the target frame;

Among them, when the thickness of the target frame is K meters, control the included angle of K degrees to enter the A target frame. For example, when the thickness of the target frame is 10m, it can control 10° to enter the A target frame, and when the target frame thickness is 2m, it can control the included angle of 2° to enter the A target frame.

In the present invention, under the premise that the displacement before landing is equivalent, the data of the model system can be directly applied to other work areas. It should be pointed out that the present invention does not describe too many technical methods that belong to the common knowledge in the field such as formation contrast and marker layer determination; in addition, for those skilled in the art, without departing from the main implementation steps of the present invention In advance, some improvements can also be made, and these should also be regarded as the protection scope of the present invention.

The present invention has been applied to more than 70 wells in oil and gas fields such as FL, FX, and HX, and the geological landing accuracy rate reaches 100%, and the calculated angle between the stratum and the trajectory is close to the actual landing control angle, which can meet the rapid guidance work on site Need; the present invention better solves the problem of rapid calculation of well deviation adjustment in the field landing stage, the method is simple and easy to implement, and has a wide range of applications, and provides an innovative technology for geosteering.

It should be understood that the sequence numbers of the steps in the above embodiments do not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiment of the present application.

The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still implement the foregoing embodiments Modifications to the technical solutions described in the examples, or equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the application, and should be included in the Within the protection scope of this application.

Claims (9)

1. A horizontal well deviation adjusting method before landing based on a marker layer and included angle dual constraint is characterized by comprising the following steps:

acquiring data of a standard well, a drilled horizontal well and a horizontal well to be drilled;

establishing a corresponding relation between a standard well and a drilled horizontal well;

obtaining a model empirical coefficient by marking the thickness h and the included angle gamma of the target point of the corresponding standard well spacing A;

establishing a mark layer and included angle chart of the standard well by using a regression equation;

calculating well deviation which is required to be adjusted from the horizontal well to be drilled to the corresponding mark layer;

controlling the track of the horizontal well to be drilled before landing according to the calculation result;

and controlling the attitude of the target A when the horizontal well to be drilled is landed.

2. The horizontal well pre-landing deviation adjusting method based on the marker layer and included angle dual constraints is characterized in that the obtaining of the data of a standard well, a drilled horizontal well and a horizontal well to be drilled comprises the following steps:

acquiring geological stratification, lithology, natural gamma, gas logging, geology and element data of a standard well;

acquiring geological stratification, lithology, natural gamma, gas logging and well deviation data table data of the drilled horizontal well;

and acquiring lithology, natural gamma, gas logging, well depth while drilling, well deviation and azimuth data of the guide horizontal well to be drilled.

3. The method for adjusting the horizontal well deviation before landing based on the marker layer and included angle dual constraint is characterized in that the method for selecting the drilled horizontal well comprises the following steps:

selecting a drilled horizontal well which has stable stratum attitude, relatively stable thickness, 250-350m displacement before landing, less than 15 degrees/100 m of average total angle change rate of a landing section track and representative accurate landing as a modeling well.

4. The horizontal well pre-landing deviation adjusting method based on the marker layer and included angle dual constraints as claimed in claim 1, wherein establishing the corresponding relationship between the standard well and the drilled horizontal well comprises:

determining all the mark layers of S1 m to the target point A by comparing the stratums of the standard well and the drilled horizontal well, and numbering the mark layers from top to bottom;

reading well depth, well deviation and azimuth data from a first mark layer of the drilled horizontal well to a target point A;

marking the depth value and the well deviation data on the well deviation data table of the drilled horizontal well to the corresponding standard well by comparing the lithology, natural gamma ray and gas logging characteristics of the marker strata of the standard well and the drilled horizontal well;

and converting the standard well depth value corresponding to the mark into the thickness h from the target point A, and converting well deviation data into an included angle gamma, wherein the included angle gamma refers to the included angle between the trajectory line and the stratum.

5. The horizontal well deviation adjusting method before landing based on the marker layer and included angle dual constraint is characterized in that the obtaining of the model empirical coefficients by marking the corresponding standard well spacing target point thickness h and the included angle gamma comprises the following steps:

drawing a cross graph of the thickness h of the target point at the included angle gamma-distance A by marking corresponding data samples of the thickness h of the target point at the standard well distance and the included angle gamma;

establishing a polynomial regression equation with the thickness h from the target A as an independent variable and the included angle gamma as a dependent variable;

model γ = Ah is obtained ³ +Bh ² + Ch +2.00 model empirical coefficients A, B, C.

6. The method for adjusting the horizontal well inclination before landing based on the marker layer and included angle dual constraint of claim 1, wherein the establishing of the marker layer and included angle chart of the standard well by using the regression equation comprises:

and drawing a plate of the standard well including well depth, natural gamma, a marker layer, lithology and an included angle from top to bottom.

7. The method for adjusting the well deviation before the horizontal well lands based on the double constraints of the mark layer and the included angle as claimed in claim 1, wherein the step of calculating the well deviation to be adjusted from the horizontal well to be drilled to the corresponding mark layer comprises the steps of:

converting an included angle gamma between the trajectory and the stratum into a well deviation which is required to be adjusted from the horizontal well to be drilled to the corresponding mark layer according to a formula gamma = 90-alpha-beta;

wherein beta is the formation apparent dip angle, and alpha is the well dip angle.

8. The horizontal well pre-landing deviation adjusting method based on the marker layer and included angle dual constraints is characterized in that the step of controlling the pre-landing trajectory of the horizontal well to be drilled according to the calculation result comprises the following steps:

calculating the result according to the stratum apparent dip angle of the previous mark layer by adopting an adjacent similar principle to obtain the stratum apparent dip angle of the current layer;

determining the well deviation from the included angle, comprising

The dip angle of adjacent layers in the actual drilling changes, if the mark layer is pushed, the next mark layer is drilled without the corresponding included angle and well slant, and the layer can be continuously explored according to the included angle gamma calculated by the chart; if the mark layer is advanced, the well deviation required by the corresponding included angle can be quickly increased according to the specified build slope rate according to the included angle gamma calculated by the chart.

9. The horizontal well deviation adjusting method before landing based on the marker layer and included angle dual constraint is characterized in that the attitude control of the target entering A when the horizontal well to be drilled is landed comprises the following steps:

determining an included angle according to the thickness of the target frame during landing;

wherein, when the thickness of the target frame is K meters, the angle of K degrees is controlled to enter the target frame A.

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