CN102562052A - Method for recognizing harm bodies of casing failure of shallow layer of close well spacing - Google Patents
Method for recognizing harm bodies of casing failure of shallow layer of close well spacing Download PDFInfo
- Publication number
- CN102562052A CN102562052A CN2012100439429A CN201210043942A CN102562052A CN 102562052 A CN102562052 A CN 102562052A CN 2012100439429 A CN2012100439429 A CN 2012100439429A CN 201210043942 A CN201210043942 A CN 201210043942A CN 102562052 A CN102562052 A CN 102562052A
- Authority
- CN
- China
- Prior art keywords
- pressure
- stress
- shallow
- layer
- harm
- 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.)
- Granted
Links
Images
Landscapes
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
- Earth Drilling (AREA)
Abstract
A method for recognizing harm bodies of casing failure of a shallow layer of a close well spacing comprises following steps: (1), determining a pressure source of a high pressure region of casing failure of the shallow layer and accordingly determining a possible harm body; (2), determining whether the region has a reservoir body or not according to a geological structure characteristics and a sand distribution condition of the region, and accordingly determining the harm body; (3), analyzing forming mechanization of the well drilling harm body of the shallow layer; (4), predicting and calculating ground stress; (5), testing rock mechanics parameters; and (6), recognizing the well drilling harm body of the shallow layer and applying stratum pressure predicting engineering. The method can be used for accurately predicting the range and the depth of the harm body and the pressure coefficient of the shallow layer, and provides accurate and detailed geological data for well drilling of a casing failure region of the shallow layer. On the basis of the geological data, a safe well drilling scheme of the region is formulated, and the method provides a powerful guarantee for safe and rapid well drilling of an old oil region.
Description
Technical field
The present invention relates to the drilling engineering technical field, particularly a kind of dense well pattern shallow-layer cover decreases the recognition methods of harm body.
Background technology
[0002] the sleeve pipe damage has all taken place in the world each oil field to some extent, comprises North America, Russia, the North Sea, South America, Southeast Asia, and China.By the end of the end of the year 2009, Daqing oil field is found about 12000 mouthfuls of casing damaged well altogether, and its middle-shallow layer casing damaged well accounts for about 30%.Sleeve pipe is prone to take place the shallow-layer cover and decreases in long-term exploitation, the injecting process under each item active force.After cover decreases; Since long-term toward the water filling of shallow-layer well section, understratum high-pressure oil gas decrease through the shallow-layer cover that point leaks outside and casing annulus sealing or sealing are not of poor quality; Deep formation oil-gas migration forms reasons such as secondary gas reservoir to shallow-layer, shallow-layer pressure also increases gradually, forms shallow-layer harm body.Shallow-layer harm body is meant at tender abnormal pressure sand body that non-exploitation reservoir forms during oil field development gradually more than two sections or immersion mud shale body.Have uncertainty because the shallow-layer cover decreases generation area, growth scope and the harm form of harm body, therefore decrease in the wellbore construction process of higher-pressure region being prone to complex accident such as water logging, well slough, bit freezing, blowout, abandoned footage at the shallow-layer cover.
Summary of the invention
In order to solve the problem that exists in the background technology; The present invention provides a kind of dense well pattern shallow-layer cover to decrease the recognition methods of harm body; This method accurately dopes harm body scope, the degree of depth and shallow-layer pressure coefficient; For the shallow-layer cover decreases district's drilling well accurate, full and accurate geologic data is provided, on this basis, formulates this block safety drilling scheme.For original oil zone drilling well safely and fast provides strong guarantee.
The technical scheme that the present invention adopts is: this dense well pattern shallow-layer cover decreases the recognition methods of harm body and comprises the following steps:
Dense well pattern shallow-layer cover decreases the recognition methods of harm body and forms Analysis on Mechanism, geostatic stress prediction and calculating and rock mechanics parameter testing through shallow-layer drilling well harm body; According to target area geological structure characteristic, sand body distribution situation, well logging and log data; Set up the survey region geological model, and confirm corresponding fringe conditions, the utilization method for numerical simulation; Predictably stressor layer abnormal conditions and reservoir stress distribution situation; Identification object region drilling well harm body, and confirm harm body influence basin, formulate the drilling well countermeasure on this basis:
(1) confirm that the shallow-layer cover decreases the higher-pressure region pressure source, confirms to have the harm body thus:
After A, shallow-layer cover decreased, water injection well was long-term toward the water filling of shallow-layer well section;
B, bottom oil reservoir high-pressure oil gas be through annular space in the sleeve pipe, decreases the some entering upper formation that leaks outside at the shallow-layer cover;
C, understratum high-pressure oil gas are migrated to top through the sleeve pipe external space;
(2) calmodulin binding domain CaM geological structure characteristic, sand body distribution situation determine whether there is reservoir bodies, confirm to exist the harm body thus;
(3) shallow-layer drilling well harm body forms Analysis on Mechanism:
Through cored in the past, data such as density log experimentizes and test.
A, mud shale layer shallow-layer drilling well harm body
Submerging test perpendicular to the stratum bedding: the variation that utilizes X-Ray to detect water saturation in the rock core is the technology of present comparative maturity; Can judge the position of water according to the X-Ray value before and after the rock sample immersion; Again by the time of measuring; Just can calculate the immersion speed of mud stone, can know from result of the test: the immersion parameter of mud stone: mud stone immersion intensity, immersed depth and immersion speed mainly receive the influence of the difference of cap rock pore pressure.
Along the interface submerging test of mud shale bedding: along perpendicular to mud stone bedding interface direction with along the submerging test of mud stone bedding interface direction; The immersion speed that mud stone has been described slows down with the increase of soaking time; Until immersion speed is zero; Immersion speed and immersed depth are the function of difference between reservoir pre ssure and injection pressure, and pressure reduction is big more, and immersion speed and immersed depth are also big more;
The mud stone water content is to the influence of its mechanical characteristic: the size of its cohesive strength of dissimilar mud shales and angle of internal friction has very big difference; But immersion its cohesive strength of back and angle of internal friction all have reduction significantly, and slope of a curve size description rock sample is to the sensitivity of immersion;
Mud shale drilling well harm body forms mechanism: injection pressure surpasses the fracture pressure of mud shale layer, and the water enchroachment (invasion) scope is fracture length and length of flooding sum;
Crack initiation model: Terzaghi pattern, Shi Difen pattern, yellow flourish cup pattern;
Horizontal joint crack initiation pattern: when water injection pressure surpassed the horizontal joint initial cracking pressure, the at first crack initiation of mud shale layer formed horizontal fracture, and preserves fluid, formed shallow-layer drilling well harm body;
B, independent sand body shallow-layer drilling well harm body
Geostatic stress derive from remaining paleostructure stress, stratum on cover the motion collision of gravity, continental plate, the water pressure gradient in the stratum etc.Therefore geostatic stress is the internal stress of objective reality in the subterranean body.In underground rock mass, exist three orthogonal main geostatic stress on direction, the vertical geostatic stress σ v that promptly causes by rock mass deadweight and the main geostatic stress σ H and the σ h of two horizontal directions.Generally speaking, three main stress bares are unequal.
The geostatic stress computation model:
Vertical geostatic stress computation model:
Switzerland geologist Heim thinks that vertical geostatic stress σ v is caused by superstratum gravity, and it is along with density of earth formations and the degree of depth and change, so the density available well-log information is obtained vertical geostatic stress:
In the formula: h is the stratum buried depth;
is the function that density of earth formations changes with depth of stratum h; G is an acceleration of gravity.
Stress calculation model flatly: Jin Nike pattern, Mattews and Kelly model, Terzaghi model, Anderson model, Neberry model, two are to not waiting ground stress model
The course folk prescription is to original place minimum principal stress that extruding draws hypothetically; Unidirectionally extruded result is exactly that the stratum receives the tectonic stress effect in one direction; And do not have tectonic stress on another direction, but in fact most applications is really not so, and tectonic stress all exists on all directions basically; And be unequal, yellow flourish cup professor of University of Petroleum studies the relational expression that has drawn following expression geostatic stress size on the basis for many years:
Geostatic stress result of calculation: utilization density log data and degree of depth data can obtain each degree of depth geostatic stress value.
The rock mechanics parameter testing:
Test for tensile strength: measure the rock tensile strength.
Single shaft is tested with triaxial stress: the parameters such as compressive strength, poisson's ratio and modulus of elasticity of measuring rock under the different confined pressures.
In independent sand body, only consider Seepage problems.
(4) shallow-layer drilling well harm body numerical simulation analysis
Finite element method is the method for numerical simulation of in field of engineering technology, using always at present.The basic thought of finite element method is that the territory of finding the solution with problem is divided into a series of unit, only depends on node to connect between the unit.The amount to be asked of unit internal point can be tried to achieve through selected functional relation interpolation by the cell node amount.Because cell configuration is simple, be easy to set up the equation between the node amount by equilibrium relation or energy, then each unit equation " group collection " is formed overall Algebraic Equation set together, can find the solution equation group after counting fringe conditions.
Seepage theory: method and dependent equation that finite element method is found the solution Seepage problems are:
The finite elements form of the discretization of generalized Darcy's law, fundamental equation, problem, the solid coupled system of three-dimensional porous MEDIA FLOW.
The dynamic (dynamical) fundamental equation of three dimensional elasticity is:
The equation of motion:
Geometric equation:
Physical equation:
Fringe conditions:
Primary condition
In the formula;
is mass density;
is damped coefficient,
and
be respectively the speed and the acceleration of i direction.
Comprehensively above-mentioned, the finite element solving equation that can obtain the solid coupled system of porous media flow is:
A, the sunykatuib analysis of mud shale number of plies value:
The levels position is a sand layers, and the position, intermediate layer is the mud shale layer, obtains material parameter and geostatic stress value through test in early stage and experiment, sets the bottom surface fixed constraint in the boundary setting, and its lap is set to stress boundary by the geostatic stress value.Crack stream is adopted in mud shale layer bit stream field in the model, and seam surface roughness coefficient is set.Its cohesive strength of mud shale immersion back all has reduction significantly with angle of internal friction, and when injection pressure pressure during greater than mud shale layer fracture pressure, the mud shale bedding is opened expansion, until pressure less than mud shale bedding initial cracking pressure., will form a shallow-layer cover and decrease the harm body because pressure falls in the open zone of mud shale bedding.
Adopt free tetrahedral grid subdivision model,, obtain the mud shale bedding through modeling software and open situation and shallow-layer cover damage harm body pressure distribution situation through finite element analysis computation.B, independent sand body numerical simulation analysis:
Exists an independently sand body in the middle of the stratum, shape approximation is the cylindroid shape, and the permeability of independent sand body, degree of porosity all greater than stratum on every side, have independently modulus of elasticity.Obtain material parameter and geostatic stress value through test in early stage and experiment, set the bottom surface fixed constraint in the boundary setting, its lap is set to stress boundary by the geostatic stress value.Darcy flow is adopted in the flow field in the model, and independent sand body is provided with different permeabilities, degree of porosity, modulus of elasticity with overall stratum.Adopt free tetrahedral grid subdivision model,, obtain the shallow-layer cover through modeling software and decrease harm body pressure distribution situation through finite element analysis computation.
The present invention has following beneficial effect: a plurality of blocks have been used dense well pattern shallow-layer cover and have been decreased the harm body recognition technology mouthful well surplus in the of 300 of constructing; Obtained significant effect; Shallow-layer harm body identification prediction rate of accuracy reached to 100%, the complicated incidence 1.67% of accident, the drilling well success rate reaches 100%; No blowout out of control takes place, and for the shallow-layer cover decreases district's safety drilling powerful guarantee is provided.
Description of drawings:
Strata pressure distribution map when Fig. 1 is a pressure source;
Fig. 2 is the pressure-plotting apart from the pressure source diverse location;
Strata pressure distribution map when Fig. 3 is two pressure sources;
Higher-pressure region harm body pressure-plotting when Fig. 4 is two pressure sources;
Strata pressure distribution map when Fig. 5 is three pressure sources;
Higher-pressure region harm body pressure-plotting when Fig. 6 is three pressure sources;
Fig. 7 is a mud shale layer physical model;
Fig. 8 is the pressure-plotting on whole stratum;
Fig. 9 is the vertical open areal map of mud shale bedding of going up;
Figure 10 is that the mud shale bedding is opened figure on the horizontal direction;
Figure 11 is a mud shale bedding pressure-plotting on the horizontal direction;
Figure 12 is the tonogram apart from the pressure source diverse location;
Figure 13 is density-well depth regression curve;
Figure 14 is high 173-152 wellblock areal geology structure and pressure source distribution map;
Figure 15 is that the finite element analysis model that is coupled is admittedly flowed in zone, high 173-152 wellblock;
Figure 16 is high 173-152 wellblock shallow-layer harm body distribution and strata pressure cloud charts;
Figure 17 is high 173-152 well strata pressure distribution isogram;
Figure 18 is middle 71-p031 wellblock areal geology structure and pressure source distribution map;
Figure 19 is middle 71-p031 wellblock shallow-layer harm body distribution and strata pressure cloud charts;
Figure 20 is the high 429-27 of western 2 fault blocks wellblock areal geology structure and pressure source distribution map
Figure 21 is vertical stress distribution cloud atlas in the high 429-27 of western 2 fault blocks wellblock and isogram;
Figure 22 is the high 429-27 of western 2 fault blocks wellblock shallow-layer harm body distribution and strata pressure cloud charts;
Figure 23 is apricot 12-4-p3712 wellblock areal geology structure and pressure source distribution map;
Figure 24 is the scope and the pressure cloud atlas of apricot 12-4-p3712 wellblock shallow-layer harm body.
The specific embodiment:
This dense well pattern shallow-layer cover decreases the recognition methods of harm body and comprises the following steps:
Dense well pattern shallow-layer cover decreases the recognition methods of harm body and forms Analysis on Mechanism, geostatic stress prediction and calculating and rock mechanics parameter testing through shallow-layer drilling well harm body; According to target area geological structure characteristic, sand body distribution situation, well logging and log data; Set up the survey region geological model, and confirm corresponding fringe conditions, the utilization method for numerical simulation; Predictably stressor layer abnormal conditions and reservoir stress distribution situation; Identification object region drilling well harm body, and confirm harm body influence basin, formulate the drilling well countermeasure on this basis:
(1) confirm that the shallow-layer cover decreases the higher-pressure region pressure source, confirms to have the harm body thus:
After A, shallow-layer cover decreased, water injection well was long-term toward the water filling of shallow-layer well section;
B, bottom oil reservoir high-pressure oil gas be through annular space in the sleeve pipe, decreases the some entering upper formation that leaks outside at the shallow-layer cover;
C, understratum high-pressure oil gas are migrated to top through the sleeve pipe external space;
(2) calmodulin binding domain CaM geological structure characteristic, sand body distribution situation determine whether there is reservoir bodies, confirm to exist the harm body thus;
(3) shallow-layer drilling well harm body forms Analysis on Mechanism:
Through cored in the past, data such as density log experimentizes and test.
A, mud shale layer shallow-layer drilling well harm body
Submerging test perpendicular to the stratum bedding: the variation that utilizes X-Ray to detect water saturation in the rock core is the technology of present comparative maturity; Can judge the position of water according to the X-Ray value before and after the rock sample immersion; Again by the time of measuring; Just can calculate the immersion speed of mud stone, can know from result of the test: the immersion parameter of mud stone: mud stone immersion intensity, immersed depth and immersion speed mainly receive the influence of the difference of cap rock pore pressure.
Along the interface submerging test of mud shale bedding: along perpendicular to mud stone bedding interface direction with along the submerging test of mud stone bedding interface direction; The immersion speed that mud stone has been described slows down with the increase of soaking time; Until immersion speed is zero; Immersion speed and immersed depth are the function of difference between reservoir pre ssure and injection pressure, and pressure reduction is big more, and immersion speed and immersed depth are also big more;
The mud stone water content is to the influence of its mechanical characteristic: the size of its cohesive strength of dissimilar mud shales and angle of internal friction has very big difference; But immersion its cohesive strength of back and angle of internal friction all have reduction significantly, and slope of a curve size description rock sample is to the sensitivity of immersion;
Mud shale drilling well harm body forms mechanism: injection pressure surpasses the fracture pressure of mud shale layer, and the water enchroachment (invasion) scope is fracture length and length of flooding sum;
Crack initiation model: Terzaghi pattern, Shi Difen pattern, yellow flourish cup pattern;
Horizontal joint crack initiation pattern: when water injection pressure surpassed the horizontal joint initial cracking pressure, the at first crack initiation of mud shale layer formed horizontal fracture, and preserves fluid, formed shallow-layer drilling well harm body;
B, independent sand body shallow-layer drilling well harm body
Geostatic stress derive from remaining paleostructure stress, stratum on cover the motion collision of gravity, continental plate, the water pressure gradient in the stratum etc.Therefore geostatic stress is the internal stress of objective reality in the subterranean body.In underground rock mass, exist three orthogonal main geostatic stress on direction, the vertical geostatic stress σ v that promptly causes by rock mass deadweight and the main geostatic stress σ H and the σ h of two horizontal directions.Generally speaking, three main stress bares are unequal.
The geostatic stress computation model:
Vertical geostatic stress computation model:
Switzerland geologist Heim thinks that vertical geostatic stress σ v is caused by superstratum gravity, and it is along with density of earth formations and the degree of depth and change, so the density available well-log information is obtained vertical geostatic stress:
In the formula: h is the stratum buried depth;
is the function that density of earth formations changes with depth of stratum h; G is an acceleration of gravity.
Stress calculation model flatly: Jin Nike pattern, Mattews and Kelly model, Terzaghi model, Anderson model, Neberry model, two are to not waiting ground stress model
The course folk prescription is to original place minimum principal stress that extruding draws hypothetically; Unidirectionally extruded result is exactly that the stratum receives the tectonic stress effect in one direction; And do not have tectonic stress on another direction, but in fact most applications is really not so, and tectonic stress all exists on all directions basically; And be unequal, yellow flourish cup professor of University of Petroleum studies the relational expression that has drawn following expression geostatic stress size on the basis for many years:
Geostatic stress result of calculation: utilization density log data and degree of depth data can obtain each degree of depth geostatic stress value.
The rock mechanics parameter testing:
Test for tensile strength: measure the rock tensile strength.
Single shaft is tested with triaxial stress: the parameters such as compressive strength, poisson's ratio and modulus of elasticity of measuring rock under the different confined pressures.
In independent sand body, only consider Seepage problems.
(4) shallow-layer drilling well harm body numerical simulation analysis
Finite element method is the method for numerical simulation of in field of engineering technology, using always at present.The basic thought of finite element method is that the territory of finding the solution with problem is divided into a series of unit, only depends on node to connect between the unit.The amount to be asked of unit internal point can be tried to achieve through selected functional relation interpolation by the cell node amount.Because cell configuration is simple, be easy to set up the equation between the node amount by equilibrium relation or energy, then each unit equation " group collection " is formed overall Algebraic Equation set together, can find the solution equation group after counting fringe conditions.
Seepage theory: method and dependent equation that finite element method is found the solution Seepage problems are:
The finite elements form of the discretization of generalized Darcy's law, fundamental equation, problem, the solid coupled system of three-dimensional porous MEDIA FLOW.
The dynamic (dynamical) fundamental equation of three dimensional elasticity is:
The equation of motion:
Geometric equation:
Physical equation:
Fringe conditions:
Primary condition
In the formula;
is mass density;
is damped coefficient,
and
be respectively the speed and the acceleration of i direction.
Comprehensively above-mentioned, the finite element solving equation that can obtain the solid coupled system of porous media flow is:
A, the sunykatuib analysis of mud shale number of plies value:
The levels position is a sand layers, and the position, intermediate layer is the mud shale layer, obtains material parameter and geostatic stress value through test in early stage and experiment, sets the bottom surface fixed constraint in the boundary setting, and its lap is set to stress boundary by the geostatic stress value.Crack stream is adopted in mud shale layer bit stream field in the model, and seam surface roughness coefficient is set.Its cohesive strength of mud shale immersion back all has reduction significantly with angle of internal friction, and when injection pressure pressure during greater than mud shale layer fracture pressure, the mud shale bedding is opened expansion, until pressure less than mud shale bedding initial cracking pressure., will form a shallow-layer cover and decrease the harm body because pressure falls in the open zone of mud shale bedding.
Adopt free tetrahedral grid subdivision model,, obtain the mud shale bedding through modeling software and open situation and shallow-layer cover damage harm body pressure distribution situation through finite element analysis computation.B, independent sand body numerical simulation analysis:
Exists an independently sand body in the middle of the stratum, shape approximation is the cylindroid shape, and the permeability of independent sand body, degree of porosity all greater than stratum on every side, have independently modulus of elasticity.Obtain material parameter and geostatic stress value through test in early stage and experiment, set the bottom surface fixed constraint in the boundary setting, its lap is set to stress boundary by the geostatic stress value.Darcy flow is adopted in the flow field in the model, and independent sand body is provided with different permeabilities, degree of porosity, modulus of elasticity with overall stratum.Adopt free tetrahedral grid subdivision model,, obtain the shallow-layer cover through modeling software and decrease harm body pressure distribution situation through finite element analysis computation.
(5) identification of shallow-layer drilling well harm body and prediction of formation pressure practical applications:
A, high 173-152 wellblock, Nan Er district
Pressure source is water 131 and water 231 wells, through the geologic structure analysis, confirms that high 173-152 wellblock, Nan Er district is independent sand body harm body, injects fluid and directly gets into sand body, progressively stores, and pressure raises gradually and spreads, and causes the shallow-layer sand body to form abnormal pressure.Entity in the model, stress-strain suppose that partly the stratum is a linear elasticity, set the bottom surface fixed constraint in the boundary setting, and its lap is set to the initial stress border by the geostatic stress value.Darcy's law is partly adopted in flow field simulation in the model; Aspect is a barrier bed about being provided with, and peripheric surface is set to the far field strata pressure, high infiltration in the sand body; Barrier bed hyposmosis all around; The pressure boundary condition of adjustment pressure source makes the pressure monitoring value error of forecast pressure value and infill well in abnormal pressure district close, calculates the stress and the seepage pressure of each node in the sand body.Set up the zone and flow the finite element analysis model that is coupled admittedly.Adopt free tetrahedral grid subdivision model; Is definite condition with the strata pressure value of prediction and the monitoring pressure value error of infill well less than 5%; Through finite element simulation calculation, identify target area drilling well harm body, and confirm just to go out to endanger body influence basin and pressure size.
B, middle 71-p031 wellblock:
Pressure source is middle 7-p10 well, and through the geologic structure analysis, the 71-p031 wellblock is a double break layer barrier structure in confirming, injects fluid and receives fault barrier, and the higher-pressure region is confined between the tomography.Analyze mechanism and pressure distribution scope that fault barrier forms the abnormal pressure district.Entity in the model, stress-strain portion hypothesis stratum is a linear elasticity, and two tomographies are set, and the mechanics parameter of tomography is different from the sand layers mechanics parameter, sets the bottom surface fixed constraint in the boundary setting, and its lap is set to stress boundary by the geostatic stress value.Darcy's law is partly adopted in flow field simulation in the model, and aspect is a barrier bed about being provided with, the tomography impervious bed, and the border, far field is a strata pressure.Set up the zone and flow the finite element analysis model that is coupled admittedly.Adopt free tetrahedral grid subdivision model, through finite element analysis computation, identify target area drilling well harm body, and confirm just to go out to endanger body influence basin and pressure size.
C, the high 429-27 of western 2 fault blocks wellblock:
Two pressure sources, through the geologic structure analysis, the high 429-27 of western 2 fault blocks wellblock shallow-layer harm body mainly is distributed in tender two sections bottom mud shale layers, near the tomography.There are three gradients in this zone on east-west, isohypse 765-775m, and the gradient is big, and is more precipitous, gets into flat zone then, increases again in the 780-790m degree of depth gradient, has two ridges at isohypse 775m and 780m position.Have two pressure sources, when injection pressure surpassed superstratum pressure, fluid was invaded along the mud shale bedding, and along stress low value area extension, along with blocking of pressure loss and tomography, no longer extend in the crack, formed partial high pressure harm body.Model at first adopts structure mechanics analysis, supposes that the stratum is a linear elasticity, sets the bottom surface fixed constraint in the boundary setting, and its lap is set to stress boundary by the geostatic stress value, analyzes the STRESS VARIATION that this geologic structure causes.Set up the zone and flow the finite element analysis model that is coupled admittedly.Adopt free tetrahedral grid subdivision model, through finite element analysis computation, identify target area drilling well harm body, and confirm just to go out to endanger body influence basin and pressure size.
D, apricot 12-4-p3712 wellblock:
Pressure source is apricot 12-4-the third 371, and through the geologic structure analysis, apricot 12-4-p3712 wellblock shallow-layer harm body mainly is distributed in tender two sections bottom mud shale layers; The horizontal bedding bedding is grown, and has 1 pressure source, when injection pressure surpasses superstratum pressure; Form the crack, fluid is invaded along the mud shale bedding, along with depth of invasion increases; Pressure loss increases, and the crack stops to extend, and forms partial high pressure harm body.Set up physical model, entity in the model, stress-strain portion hypothesis stratum is a linear elasticity, sets the bottom surface fixed constraint in the boundary setting, its lap is set to stress boundary by the geostatic stress value.Crack stream is adopted in the flow field in the model, and the seam face is provided with the pressure drop function, sets up the zone and flows the finite element analysis model that is coupled admittedly.Adopt free tetrahedral grid subdivision model, through finite element analysis computation, identify target area drilling well harm body, and confirm just to go out to endanger body influence basin and pressure size.Middle 7-10 well was found 242 meters bad breaks in 1975, and enforcement in 1981 is scrapped.Middle 7-more 10 wells finds that in 1993 shallow-layer (206-351 rice) leaks outside, 206 meters bad breaks of discovery in 1997.High 145-37 well, high 145-373 well are found 183 meters sleeve pipe bad breaks in May, 2000.Above-mentioned four-hole well was once long-term toward the water filling of shallow-layer (183-242 rice) well section, and middle 7-more 10 wellblock east-west directions grow 2 tomographies, sandstone receives fault barrier, and the higher-pressure region is confined between the tomography.Form shallow-layer harm body.Because middle 7-more 10 wells must overlap the damage type for leaking outside, and therefore thinks this well for forming the main pressure source of higher-pressure region, its excess-three mouth well is less important pressure source.Through dense well pattern shallow-layer cover being decreased the identification of harm body, confirm harm body border should be in distance 7-10, middle 7-more 10, in 250 meters of the high 145-37,373 wells, the degree of depth is at 160-260 rice, pressure is at 1.55-1.1.75g/ cm3.For cloth at the 6 mouthful wells of harm on the body, through take different increase the weight of well depth with the density design, suitably increase dark under the top layer, protective casing, former well pressure release down, adopt and avoid cover around the barrier orientation and decrease countermeasures such as harm body, all drilling wells are successful.
Claims (1)
1. a dense well pattern shallow-layer cover decreases the recognition methods of harm body, and this method comprises the following steps:
Dense well pattern shallow-layer cover decreases the recognition methods of harm body and forms Analysis on Mechanism, geostatic stress prediction and calculating and rock mechanics parameter testing through shallow-layer drilling well harm body; According to target area geological structure characteristic, sand body distribution situation, well logging and log data; Set up the survey region geological model, and confirm corresponding fringe conditions, the utilization method for numerical simulation; Predictably stressor layer abnormal conditions and reservoir stress distribution situation; Identification object region drilling well harm body, and confirm harm body influence basin, formulate the drilling well countermeasure on this basis:
(1) confirm that the shallow-layer cover decreases the higher-pressure region pressure source, confirms to have the harm body thus:
After A, shallow-layer cover decreased, water injection well was long-term toward the water filling of shallow-layer well section;
B, bottom oil reservoir high-pressure oil gas be through annular space in the sleeve pipe, decreases the some entering upper formation that leaks outside at the shallow-layer cover;
C, understratum high-pressure oil gas are migrated to top through the sleeve pipe external space;
(2) calmodulin binding domain CaM geological structure characteristic, sand body distribution situation determine whether there is reservoir bodies, confirm to exist the harm body thus;
(3) shallow-layer drilling well harm body forms Analysis on Mechanism:
Through cored in the past, data such as density log experimentizes and test;
A, mud shale layer shallow-layer drilling well harm body:
Submerging test perpendicular to the stratum bedding: the variation that utilizes X-Ray to detect water saturation in the rock core is the technology of present comparative maturity; Can judge the position of water according to the X-Ray value before and after the rock sample immersion; Again by the time of measuring; Just can calculate the immersion speed of mud stone, can know from result of the test: the immersion parameter of mud stone: mud stone immersion intensity, immersed depth and immersion speed mainly receive the influence of the difference of cap rock pore pressure;
Along the interface submerging test of mud shale bedding: along perpendicular to mud stone bedding interface direction with along the submerging test of mud stone bedding interface direction; The immersion speed that mud stone has been described slows down with the increase of soaking time; Until immersion speed is zero; Immersion speed and immersed depth are the function of difference between reservoir pre ssure and injection pressure, and pressure reduction is big more, and immersion speed and immersed depth are also big more;
The mud stone water content is to the influence of its mechanical characteristic: the size of its cohesive strength of dissimilar mud shales and angle of internal friction has very big difference; But immersion its cohesive strength of back and angle of internal friction all have reduction significantly, and slope of a curve size description rock sample is to the sensitivity of immersion;
Mud shale drilling well harm body forms mechanism: injection pressure surpasses the fracture pressure of mud shale layer, and the water enchroachment (invasion) scope is fracture length and length of flooding sum;
Crack initiation model: Terzaghi pattern, Shi Difen pattern, yellow flourish cup pattern;
Horizontal joint crack initiation pattern: when water injection pressure surpassed the horizontal joint initial cracking pressure, the at first crack initiation of mud shale layer formed horizontal fracture, and preserves fluid, formed shallow-layer drilling well harm body;
B, independent sand body shallow-layer drilling well harm body:
Geostatic stress derive from remaining paleostructure stress, stratum on cover the motion collision of gravity, continental plate, the water pressure gradient in the stratum etc.; Therefore geostatic stress is the internal stress of objective reality in the subterranean body; In underground rock mass, exist three orthogonal main geostatic stress on direction, the vertical geostatic stress σ v that promptly causes by rock mass deadweight and the main geostatic stress σ H and the σ h of two horizontal directions;
Generally speaking, three main stress bares are unequal;
The geostatic stress computation model:
Vertical geostatic stress computation model:
Switzerland geologist Heim thinks that vertical geostatic stress σ v is caused by superstratum gravity, and it is along with density of earth formations and the degree of depth and change, so the density available well-log information is obtained vertical geostatic stress:
In the formula: h is the stratum buried depth;
is the function that density of earth formations changes with depth of stratum h; G is an acceleration of gravity;
Stress calculation model flatly: Jin Nike pattern, Mattews and Kelly model, Terzaghi model, Anderson model, Neberry model, two are to not waiting ground stress model;
The course folk prescription is to original place minimum principal stress that extruding draws hypothetically; Unidirectionally extruded result is exactly that the stratum receives the tectonic stress effect in one direction; And there is not tectonic stress on another direction; Tectonic stress all exists on all directions basically, and is unequal, the relational expression of geostatic stress size:
Geostatic stress result of calculation: utilization density log data and degree of depth data can obtain each degree of depth geostatic stress value;
The rock mechanics parameter testing:
Test for tensile strength: measure the rock tensile strength;
Single shaft is tested with triaxial stress: the parameters such as compressive strength, poisson's ratio and modulus of elasticity of measuring rock under the different confined pressures; In independent sand body, only consider Seepage problems;
(4) shallow-layer drilling well harm body numerical simulation analysis:
Finite element method is present method for numerical simulation commonly used in field of engineering technology, and the basic thought of finite element method is that the territory of finding the solution with problem is divided into a series of unit, only depends on node to connect between the unit; The amount to be asked of unit internal point can be tried to achieve through selected functional relation interpolation by the cell node amount; Because cell configuration is simple, be easy to set up the equation between the node amount by equilibrium relation or energy, then each unit equation " group collection " is formed overall Algebraic Equation set together, can find the solution equation group after counting fringe conditions;
Seepage theory: method and dependent equation that finite element method is found the solution Seepage problems are:
The finite elements form of the discretization of generalized Darcy's law, fundamental equation, problem, the solid coupled system of three-dimensional porous MEDIA FLOW;
The dynamic (dynamical) fundamental equation of three dimensional elasticity is:
The equation of motion:
Geometric equation:
Physical equation:
Fringe conditions:
Primary condition
(in
domain)
(in
domain)
In the formula;
is mass density;
is damped coefficient,
and
be respectively the speed and the acceleration of i direction;
Comprehensively above-mentioned, the finite element solving equation that can obtain the solid coupled system of porous media flow is:
A, the sunykatuib analysis of mud shale number of plies value:
The levels position is a sand layers, and the position, intermediate layer is the mud shale layer, obtains material parameter and geostatic stress value through test in early stage and experiment, sets the bottom surface fixed constraint in the boundary setting, and its lap is set to stress boundary by the geostatic stress value; Crack stream is adopted in mud shale layer bit stream field in the model, and seam surface roughness coefficient is set; Its cohesive strength of mud shale immersion back all has reduction significantly with angle of internal friction, and when injection pressure pressure during greater than mud shale layer fracture pressure, the mud shale bedding is opened expansion, until pressure less than mud shale bedding initial cracking pressure; , will form a shallow-layer cover and decrease the harm body because pressure falls in the open zone of mud shale bedding;
Adopt free tetrahedral grid subdivision model,, obtain the mud shale bedding through modeling software and open situation and shallow-layer cover damage harm body pressure distribution situation through finite element analysis computation; B, independent sand body numerical simulation analysis:
Exists an independently sand body in the middle of the stratum, shape approximation is the cylindroid shape, and the permeability of independent sand body, degree of porosity all greater than stratum on every side, have independently modulus of elasticity; Obtain material parameter and geostatic stress value through test in early stage and experiment, set the bottom surface fixed constraint in the boundary setting, its lap is set to stress boundary by the geostatic stress value; Darcy flow is adopted in the flow field in the model, and independent sand body is provided with different permeabilities, degree of porosity, modulus of elasticity with overall stratum; Adopt free tetrahedral grid subdivision model,, obtain the shallow-layer cover through modeling software and decrease harm body pressure distribution situation through finite element analysis computation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210043942.9A CN102562052B (en) | 2012-02-26 | 2012-02-26 | Method for recognizing harm bodies of casing failure of shallow layer of close well spacing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210043942.9A CN102562052B (en) | 2012-02-26 | 2012-02-26 | Method for recognizing harm bodies of casing failure of shallow layer of close well spacing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102562052A true CN102562052A (en) | 2012-07-11 |
| CN102562052B CN102562052B (en) | 2016-02-03 |
Family
ID=46408489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210043942.9A Active CN102562052B (en) | 2012-02-26 | 2012-02-26 | Method for recognizing harm bodies of casing failure of shallow layer of close well spacing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102562052B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104318032A (en) * | 2014-11-01 | 2015-01-28 | 西南石油大学 | Method for calculating oil field casing damage under fluid-solid coupling effect |
| CN106199712A (en) * | 2016-06-29 | 2016-12-07 | 中国石油天然气集团公司 | A kind of method and device determining pressure break casing deformation region |
| CN106251075A (en) * | 2016-08-04 | 2016-12-21 | 中国石油天然气股份有限公司 | A kind of oil field block set damages Risk-warning and analyzes method |
| CN106761647A (en) * | 2017-01-13 | 2017-05-31 | 黄仲尧 | A kind of method that plane transforms area after estimation shale reservoir pressure |
| NL2035459A (en) * | 2022-07-25 | 2024-02-02 | Inst Rock & Soil Mech Cas | Method for determining optimal well spacing of advanced exhaust wells for shallow gas-geological disaster prevention |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001000962A1 (en) * | 1999-06-23 | 2001-01-04 | Schlumberger Holdings Limited | Cavity stability prediction method for wellbores |
| NL1020253C2 (en) * | 2001-03-28 | 2004-04-20 | Halliburton Energy Serv Inc | Iterative drilling simulation method for improved economic decision making. |
| US7032689B2 (en) * | 1996-03-25 | 2006-04-25 | Halliburton Energy Services, Inc. | Method and system for predicting performance of a drilling system of a given formation |
-
2012
- 2012-02-26 CN CN201210043942.9A patent/CN102562052B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7032689B2 (en) * | 1996-03-25 | 2006-04-25 | Halliburton Energy Services, Inc. | Method and system for predicting performance of a drilling system of a given formation |
| WO2001000962A1 (en) * | 1999-06-23 | 2001-01-04 | Schlumberger Holdings Limited | Cavity stability prediction method for wellbores |
| NL1020253C2 (en) * | 2001-03-28 | 2004-04-20 | Halliburton Energy Serv Inc | Iterative drilling simulation method for improved economic decision making. |
Non-Patent Citations (5)
| Title |
|---|
| 崔孝秉等: "注水油田套管损坏区套管损坏预测法", 《石油大学学报（自然科学版）》 * |
| 李士斌等: "套管损坏井段泥岩浸水规律试验研究", 《天然气工业》 * |
| 艾池: "套管损坏机理及理论模型与模拟计算", 《中国优秀博硕士学位论文全文数据库（博士）工程科技I辑》 * |
| 艾池等: "大庆油田泥岩浸水速度试验", 《石油钻采工艺》 * |
| 许涛等: "高压注水引起套损的机理研究", 《断块油气田》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104318032A (en) * | 2014-11-01 | 2015-01-28 | 西南石油大学 | Method for calculating oil field casing damage under fluid-solid coupling effect |
| CN106199712A (en) * | 2016-06-29 | 2016-12-07 | 中国石油天然气集团公司 | A kind of method and device determining pressure break casing deformation region |
| CN106199712B (en) * | 2016-06-29 | 2018-06-01 | 中国石油天然气集团公司 | A kind of method and device in definite pressure break casing deformation region |
| CN106251075A (en) * | 2016-08-04 | 2016-12-21 | 中国石油天然气股份有限公司 | A kind of oil field block set damages Risk-warning and analyzes method |
| CN106251075B (en) * | 2016-08-04 | 2020-05-19 | 中国石油天然气股份有限公司 | Oil field block casing loss risk early warning analysis method |
| CN106761647A (en) * | 2017-01-13 | 2017-05-31 | 黄仲尧 | A kind of method that plane transforms area after estimation shale reservoir pressure |
| CN106761647B (en) * | 2017-01-13 | 2020-08-14 | 中国石油化工股份有限公司 | Method for estimating planar reconstruction area after shale reservoir lamination |
| NL2035459A (en) * | 2022-07-25 | 2024-02-02 | Inst Rock & Soil Mech Cas | Method for determining optimal well spacing of advanced exhaust wells for shallow gas-geological disaster prevention |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102562052B (en) | 2016-02-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Bauer et al. | Overview of microseismic response to CO2 injection into the Mt. Simon saline reservoir at the Illinois Basin-Decatur Project | |
| CN105672971B (en) | A kind of Reservoir Fracture Opening pressure, open order and water injection pressure Forecasting Methodology | |
| CN106285646B (en) | Drilling well loss horizon recognition methods based on multi-information fusion | |
| Iding et al. | Evaluating the impact of fractures on the long-term performance of the In Salah CO2 storage site | |
| CN104992468A (en) | Fracture-cavern type carbonate hydrocarbon reservoir three-dimensional geological modeling method | |
| Zeng et al. | Influence of fractures on the development of low-permeability sandstone reservoirs: A case study from the Taizhao district, Daqing Oilfield, China | |
| Elenius et al. | Assessment of CO2 storage capacity based on sparse data: Skade Formation | |
| CN102562052B (en) | Method for recognizing harm bodies of casing failure of shallow layer of close well spacing | |
| Firme et al. | Mechanical behavior of carbonate reservoirs with single karst cavities | |
| Xue et al. | A combined method for evaluation and prediction on permeability in coal seams during enhanced methane recovery by pressure-relieved method | |
| Cui et al. | Resistance of caprock to hydraulic fracturing due to CO2 injection into sand lens reservoirs | |
| Gillespie et al. | Introduction: geology of fractured reservoirs | |
| Rashid et al. | The effect of fracturing on permeability in carbonate reservoir rocks | |
| Montegrossi et al. | 3D natural state model of the Menengai geothermal system, Kenya | |
| Zeng et al. | A review of the genesis, evolution, and prediction of natural fractures in deep tight sandstones of China | |
| Han et al. | Development and calibrations of a coupled reservoir geomechanic model for Valhall field | |
| Zechner et al. | Salt dissolution potential estimated from two-dimensional vertical thermohaline flow and transport modeling along a Transylvanian salt diapir, Romania | |
| Haghi et al. | A case study for HCL-based fracturing and stress determination: A Deformation/Diffusion/Thermal approach | |
| Fang et al. | Friction-permeability relationships for reservoir caprocks | |
| Ezati et al. | Evaluation of faults reactivation tenacity in one of the low-pressure SW Iranian carbonate reservoirs: an IOR viewpoint | |
| Bjørnarå et al. | Capturing the coupled hydro-mechanical processes occurring during CO2 injection–example from In Salah | |
| Meneses Rioseco et al. | 3D thermo‐hydro‐mechanical simulation of the behaviour of a naturally fractured petrothermal reservoir in deep Upper Jurassic carbonates of the Bavarian Molasse Basin–Case study Geretsried | |
| Zhu et al. | Computer modeling of gas shale reservoirs basing on dynamic mechanical characteristics-a case study of well no. 202 in weiyuan area of sichuan basin | |
| McConville | Subsurface Pressure Modeling of Saltwater Disposal for the Arbuckle and Timbered Hills-Basement System, Anadarko Shelf, Oklahoma | |
| Nygaard et al. | Geomechanical simulation of CO2 leakage and cap rock remediation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |