CN101592925A - A kind of sea pierces the control method that riser pipe under the method is rationally gone into the mud degree of depth - Google Patents

Abstract

The present invention relates to a kind of sea and pierce the control method that riser pipe under the method is rationally gone into the mud degree of depth, it may further comprise the steps: 1) go into the seafloor soil parameter and the drilling engineering parameter of the position, well site that the mud depth control system collects according to piercing riser pipe under the method, calculate the bond F between seafloor soil and the cement mantle _sCalculating formula; 2) go into the drilling engineering parameter that the mud depth control system collects according to piercing under the method riser pipe, calculate bond F between riser pipe and the cement mantle _cCalculating formula; 3) foundation described step 1) and the 2) F that draws _sAnd F _c, and the riser pipe that provides during in conjunction with drilling design well cementation Hou Ning time t ₀, and the well head load W that collects draws under the method for piercing riser pipe and rationally goes into the mud depth H.The riser pipe that the present invention determines such as the mud degree of depth are objective and accurate, are applicable to different waters.

Description

A kind of sea pierces the control method that riser pipe under the method is rationally gone into the mud degree of depth

Technical field

The present invention relates to riser pipe and rationally go into the control method of the mud degree of depth, especially a kind of sea pierces the control method that riser pipe under the method is rationally gone into the mud degree of depth.

Background technology

At sea in the exploration of oil, the mud degree of depth of going into of drilling riser plays crucial effects for exploration, the exploitation of whole oil, because if it is too small to go into the mud degree of depth, and marine complex accident such as can cause the well head unstability, sink; If it is excessive to go into the mud degree of depth, then can cause the waste on the fund.At present, the selection of drilling riser being gone into the mud degree of depth generally is according to the operation marine site drilling data of mid-early stage, relies on subjective experience to select to determine.But the seafloor soil character of different waters is inequality, this just make rely on subjective experience select and definite drilling riser to go into the mud degree of depth be irrational, and can pierce operation to the offshore drilling riser pipe and bring great risk.So, how to determine that the offshore drilling riser pipe rationally goes into the calculating of the mud degree of depth and control method and become a problem that urgency is to be solved in the offshore oil exploration development technique.

Summary of the invention

At the problems referred to above, the purpose of this invention is to provide a kind of sea of can accurately objective definite drilling riser going into the mud degree of depth and pierce the control method that riser pipe under the method is rationally gone into the mud degree of depth.

For achieving the above object, the present invention takes following technical scheme: a kind of sea pierces the control method that riser pipe under the method is rationally gone into the mud degree of depth, it is characterized in that: it may further comprise the steps: 1) go into the seafloor soil parameter and the drilling engineering parameter of the position, well site that the mud depth control system collects according to piercing riser pipe under the method, calculate the bond F between seafloor soil and the cement mantle _sCalculating formula be:

Wherein, F _sBe the bond between cement mantle and the seafloor soil [kN]; C is the cohesive strength [MPa] of seafloor soil;

Angle of internal friction [degree] for seafloor soil; h ₁Buried depth [m] for seafloor soil; T be riser pipe well cementation the Hou Ning time [hour]; Mine water mud temperature [degree] when T is well cementation; D _sBe borehole diameter [m]; Q is used cement intensity [MPa]; 2) go into the drilling engineering parameter that the mud depth control system collects according to piercing under the method riser pipe, calculate bond F between riser pipe and the cement mantle _cCalculating formula be:

$F_c=b_3\·q^{a_{2}T}\·\ln b_{2}t\·D^{a_4{h}_2}$

Wherein, F _cBe the bond between riser pipe and the cement mantle [kN]; T be riser pipe well cementation the Hou Ning time [hour]; Mine water mud temperature [degree] when T is well cementation; D is riser pipe diameter [m]; h ₂For riser pipe is gone into the mud degree of depth [m]; Q is used cement intensity [MPa]; a ₁, a ₂, a ₃, a ₄, b ₁, b ₂And b ₃According to the definite value that obtains after the statistics that experimentizes of the seafloor soil character under different waters and the sea conditions; 3) foundation described step 1) and the 2) F that draws _sAnd F _c, and the riser pipe that provides during in conjunction with drilling design well cementation Hou Ning time t ₀, and the well head load W that collects obtains piercing under the method riser pipe and rationally goes into the mud depth H; Work as t=t ₀, $F_{{\mathrm{st}}_0}\≥W$ The time, by the F in the step 1) _sCan get:

Work as t=t ₀, $F_{{\mathrm{ct}}_0}\≥W$ The time, by step 2) in F _cCan get:

$h_2\≥\frac{\mathrm{lgW}-\lg [b_3\·q^{a_{2}T}\·\ln b_2{t}_0]}{a_4\mathrm{lgD}}.$

The riser pipe that pierces under the method in the described step 3) is rationally gone into the mud depth H and is:

The present invention is owing to take above technical scheme, it has the following advantages: because the present invention is seafloor soil parameter and drilling engineering parameter according to position, actual well site, determine that drilling riser goes into the mud degree of depth, therefore determine that the result is accurately objective, save construction cost, reduced because of riser pipe and gone into the marine accident that the mud degree of depth causes.

Embodiment

Below in conjunction with embodiment, the present invention is described in detail.

The inventive method comprises the steps:

1) goes into the seafloor soil parameter and the drilling engineering parameter of the position, well site that the mud depth control system collects according to piercing riser pipe under the method, calculate the bond F between seafloor soil and the cement mantle _s, wherein the seafloor soil parameter comprises data such as seafloor soil cohesive strength and angle of internal friction; Drilling engineering parameter comprises data such as cementing slurry performance, well head load (preventer load) and Hou Ning time.Bond F between seafloor soil and the cement mantle _sCalculating formula be:

Wherein,

F _sBe the bond between cement mantle and the seafloor soil [kN];

C is the cohesive strength [MPa] of seafloor soil;

Angle of internal friction [degree] for seafloor soil;

h ₁Buried depth [m] for seafloor soil;

T be riser pipe well cementation the Hou Ning time [hour];

Mine water mud temperature [degree] when T is well cementation;

D _sBe borehole diameter [m];

Q is used cement intensity [MPa];

a ₁Be design factor;

a ₂Be design factor;

a ₃Be design factor;

b ₁Be design factor;

b ₂Be design factor.

2) according to character and the riser pipe size of the well cementation in the drilling engineering parameter, calculate bond F between riser pipe and the cement mantle with grout _cCalculating formula be:

$F_c=b_3\·q^{a_{2}T}\·\ln b_{2}t\·D^{a_4{h}_2}---\left(2\right)$

Wherein,

F _cBe the bond between riser pipe and the cement mantle [kN];

T be riser pipe well cementation the Hou Ning time [hour];

Mine water mud temperature [degree] when T is well cementation;

D is riser pipe diameter [m];

h ₂For riser pipe is gone into the mud degree of depth [m];

Q is used cement intensity [MPa];

a ₂Be design factor;

a ₄Be design factor;

b ₂Be design factor;

b ₃Be design factor.

Above-mentioned a ₁, a ₂, a ₃, a ₄, b ₁, b ₂And b ₃According to seafloor soil character under different waters and the sea conditions experimentize the statistics after obtain, be certain value.

3) according to step 1) and 2) seafloor soil that draws and the bond F between the cement mantle _sAnd the bond F between riser pipe and the cement mantle _c, and the riser pipe that provides during in conjunction with drilling design well cementation Hou Ning time t ₀, and the well head load W that collects calculates and pierces under the method riser pipe and reasonably go into the mud depth H, it is calculated as follows:

Work as t=t ₀, $F_{{\mathrm{st}}_0}\≥W$ The time, can get by formula (1):

So:

Work as t=t ₀, $F_{{\mathrm{ct}}_0}\≥W$ The time, can get by formula (2):

$h_2\≥\frac{\mathrm{lgW}-\lg [b_3\·q^{a_{2}T}\·\ln b_2{t}_0]}{a_4\mathrm{lgD}}$

So: $h_{2\min }=\frac{\mathrm{lgW}-\lg [b_3\·q^{a_{2}T}\·\ln b_2{t}_0]}{a_4\mathrm{lgD}}$

Then piercing under the method riser pipe, reasonably to go into the mud depth H be h _1min, h _2minAmong maximal value, i.e. H=Max{h _1min, h _2min.

Claims (2)

1, a kind of sea pierces the control method that riser pipe under the method is rationally gone into the mud degree of depth, and it is characterized in that: it may further comprise the steps:

1) goes into the seafloor soil parameter and the drilling engineering parameter of the position, well site that the mud depth control system collects according to piercing riser pipe under the method, calculate the bond F between seafloor soil and the cement mantle _sCalculating formula be:

Wherein,

F _sBe the bond between cement mantle and the seafloor soil [kN];

C is the cohesive strength [MPa] of seafloor soil;

Angle of internal friction [degree] for seafloor soil;

h ₁Buried depth [m] for seafloor soil;

T be riser pipe well cementation the Hou Ning time [hour];

Mine water mud temperature [degree] when T is well cementation;

D _sBe borehole diameter [m];

Q is used cement intensity [MPa];

2) go into the drilling engineering parameter that the mud depth control system collects according to piercing under the method riser pipe, calculate bond F between riser pipe and the cement mantle _cCalculating formula be:

$F_c=b_3\·q^{a_{2}T}\·\ln b_{2}t\·D^{a_4{h}_2}$

Wherein,

F _cBe the bond between riser pipe and the cement mantle [kN];

T be riser pipe well cementation the Hou Ning time [hour];

Mine water mud temperature [degree] when T is well cementation;

D is riser pipe diameter [m];

h ₂For riser pipe is gone into the mud degree of depth [m];

Q is used cement intensity [MPa];

a ₁, a ₂, a ₃, a ₄, b ₁, b ₂And b ₃According to the definite value that obtains after the statistics that experimentizes of the seafloor soil character under different waters and the sea conditions;

3) foundation described step 1) and the 2) F that draws _sAnd F _c, and the riser pipe that provides during in conjunction with drilling design well cementation Hou Ning time t ₀, and the well head load W that collects obtains piercing under the method riser pipe and rationally goes into the mud depth H;

Work as t=t ₀, $F_{{\mathrm{st}}_0}\≥W$ The time, by the F in the step 1) _sCan get:

Work as t=t ₀, $F_{{\mathrm{ct}}_0}\≥W$ The time, by step 2) in F _cCan get:

$h_2\≥\frac{\mathrm{lgW}-\lg [b_3\·q^{a_{2}T}\·\ln b_2{t}_0]}{a_4\mathrm{lgD}}.$

2, a kind of sea as claimed in claim 1 pierces the control method that riser pipe under the method is rationally gone into the mud degree of depth, it is characterized in that: the riser pipe that pierces under the method in the described step 3) is rationally gone into the mud depth H and is: