CN106682790A - Superficial layer heavy oil reservoir single-phase flow screw pump lifting prejudgment method - Google Patents

Abstract

The present invention discloses a superficial layer heavy oil reservoir single-phase flow screw pump lifting prejudgment method. The method comprises the following steps: selecting an oil well with a suitable depth for production of a screw pump, determining relevant parameters of the produced and developed oil reservoir oil well, determining the lift and the lifting speed of the screw pump, and calculating the gravity pressure loss; performing subsection calculation of the oil well, and performing subsection iteration calculation of the frictional resistance loss of each section; performing summation of the frictional resistance loss of each section to obtain a total frictional resistance loss, and performing summation of the total frictional resistance loss and the gravity pressure loss to obtain a linear loss, comparing the linear loss with the lift of the screw pump obtained in the step 2, if the linear loss is larger than the lift of the screw pump, allowing the screw pump not to be lifted; and or else, lifting the screw pump. The superficial layer heavy oil reservoir single-phase flow screw pump lifting prejudgment method is a method for determining whether the screw pump is lifted or not aiming at the superficial layer heavy oil reservoir with high crude oil viscosity and free from gas and water so as to give a certain guide for the determination of whether the screw pump is employed for production and development of the field superficial layer heavy oil or not.

Description

A kind of pre-judging method of Shallow Heavy Oil Reservoir single-phase flow screw pump lifting

Technical field

The present invention relates to a kind of pre-judging method of Shallow Heavy Oil Reservoir single-phase flow screw pump lifting, belongs to oilfield exploitation technology Field.

Background technology

For the production development of Shallow Heavy Oil Reservoir, flowing capacity of oilwell is limited, and it is conventional handss the means such as to take out using machine Section.In the application of various mechanical pumps, screw pump is due to its remarkable performance-high pump efficiency, and ground installation is simple, pollution-free, make an uproar Sound is little, and the viscosity of crude scope of adaptation is wide, and the advantage such as easy to operate is carried out the production development of shallow oil reservoir by wide hair.Spiral shell The superior performance of bar pump, also resulting in its applicable elements has certain restriction.The viscosity of crude model that general screw pump can be lifted Enclose and be less than 8000mPas, range of lift is usually within 1800m, although also have the screw pump of ultradeep well at this stage, but Generalization itself is less.When viscous crude lifting production is carried out to a bite well, it is impossible to correctly select lifting pump, can it is invisible it Between increase workload；Screw pump is have selected, perhaps over loading delivery can destroy screw pump, so as to cause the economic of oil field unit to damage Lose.

For this reason, it may be necessary to methodology is judging whether to be produced using screw pump, and this method is for not containing The production development of gas, water-free outlying Shallow Heavy Oil Reservoir block.

The content of the invention

To solve technical problem of the prior art, the present invention provides a kind of Shallow Heavy Oil Reservoir single-phase flow screw pump lifting Pre-judging method, the method is higher for viscosity of crude, and can gassiness, water-free Shallow Heavy Oil Reservoir, not adopt spiral shell A kind of determination methods of bar pump lifting production, are whether live shallow layer thick oil gives certain finger using screw pump production development Lead.

The present invention solves the technical scheme that adopted of above-mentioned technical problem：A kind of Shallow Heavy Oil Reservoir single-phase flow screw pump The pre-judging method of lifting, the method is comprised the following steps：

Step one, the oil well of selection Suitable depth carry out screw pump production, and the wherein depth of oil well is less than or equal to 1800 Rice；

Step 2, determine the oil reservoir oil well relevant parameter of production development, and determine the lift of screw pump, lifting speed, institute State oil reservoir oil well relevant parameter to glue including oil reservoir depth, the daily output, tubing diameter, oil pumping shank diameter, fluid density, shaft bottom crude oil Degree；

Inclination angle during step 3, acquisition oil density, local gravity acceleration value and oilwell drilling with stratum, Carry out calculating gravity crushing；

Step 4, oil well is carried out into segmentation calculating, per section of liquid viscosity is calculated respectively；

Step 5, the liquid viscosity by per section and following formula calculate per section of Reynolds number, then look into Moody chart acquisition accordingly Resistance coefficient；

In formula：Re is Reynolds number, nondimensional number；v_mFor average speed, m/s；D is oil pumping shank diameter, m；D is that oil pipe is straight Footpath, m；ρ_lFor fluid density, kg/m³；μ_lFor liquid viscosity, mPas；

Step 6, the resistance coefficient obtained by above-mentioned steps and following formula calculate per section of friction pressure gradient, then obtain Per section of friction loss；

In formula：τ_fFor friction pressure gradient, Pa/m；λ is resistance coefficient, zero dimension；v_lBe the pipeline section average pressure and Under mean temperature, the mean flow rate of liquid phase, m/s；ρ_lFor fluid density, kg/m³；D is tubing diameter, m；D is oil pumping shank diameter, m；

Step 7, carrying out suing for peace by per section of friction loss obtains total friction loss, then by total friction loss and weight Force damage summation and obtain linear loss；

Step 8, the lift of the screw pump for obtaining linear loss and step 2 are compared, if linear loss is more than spiral shell Bar pump lift, i.e. screw pump can not be lifted；Conversely, screw pump can be used for lifting.

It is further that the step 4 is specially：

A, oil reservoir depth is divided into into some sections,

B, the viscous kelvin relation of on-site measurement and geothermal gradient；

C, the temperature that per section is determined according to per section of depth；

D, the liquid viscosity for finally determining per section.

Beneficial effects of the present invention：The method is higher for viscosity of crude, not gassiness, water-free shallow layer thick oil oil Hide, screw pump can be adopted to lift a kind of determination methods of production, be whether live shallow layer thick oil adopts screw pump production development Give certain guidance.

Specific embodiment

A kind of pre-judging method of Shallow Heavy Oil Reservoir single-phase flow screw pump lifting of the present invention, the method includes following step Suddenly：

Step one, the oil well of selection Suitable depth carry out screw pump production, and the wherein depth of oil well is less than or equal to 1800 Rice；Because oil well of the well depth more than 1800m should not carry out oil pumping production using screw pump；

Step 2, determine the oil reservoir oil well relevant parameter of production development, and determine the lift of screw pump, lifting speed, institute (it is that profit is mixed including oil reservoir depth, the daily output, tubing diameter, oil pumping shank diameter, fluid density to state oil reservoir oil well relevant parameter Close liquid average density), shaft bottom viscosity of crude；Wherein oil reservoir depth can calculate the lift of screw pump, such as 1600 meters of lift For 16MPA, its daily output, tubing diameter, oil pumping shank diameter can pass through the lifting general formula (flow/pipeline cross section of pipe flow Product is exactly linear velocity) determine lifting speed；

Inclination angle during step 3, acquisition oil density, local gravity acceleration value and oilwell drilling with stratum, Carry out calculating gravity crushing；

Step 4, oil well is carried out into segmentation calculating；Due to the presence of geothermal gradient, viscosity of crude wherein in lifting process Rise with the decline of temperature, increased flowing frictional resistance, need consider formation temperature affect, introduce crude oil viscous kelvin relation and Geothermal gradient, i.e., calculate friction loss with segmentation, and the meansigma methodss that viscosity is taken in each segment distance carry out calculating；Calculate respectively every The liquid viscosity of section；

Step 5, the liquid viscosity by per section and following formula calculate per section of Reynolds number, then look into Moody chart acquisition accordingly Resistance coefficient；

In formula：Re is Reynolds number, nondimensional number；v_mFor average speed, m/s；D is oil pumping shank diameter, m；D is that oil pipe is straight Footpath, m；ρ_lFor fluid density, kg/m³；μ_lFor liquid viscosity, mPas；

Average speed v_mThe lifting speed that as step 2 determines；

Wherein Moody chart such as table 1：

Table 1：The corresponding relation of Reynolds number and resistance coefficient

Step 6, the resistance coefficient obtained by above-mentioned steps and following formula calculate per section of friction pressure gradient, then obtain Per section of friction loss；Wherein because being single-phase flow lifting, not gassiness, not aqueous in oil reservoir oil-producing, therefore adopt Griffith Method, the formula of seeing below carries out the calculating of friction drag and obtains relevant parameter：

In formula：τ_fFor friction pressure gradient, Pa/m；λ is resistance coefficient, zero dimension；v_lBe the pipeline section average pressure and Under mean temperature, the mean flow rate of liquid phase, m/s；ρ_lFor fluid density, kg/m³；D is tubing diameter, m；D is oil pumping shank diameter, m。

The mean flow rate of liquid phase is the lifting speed of step 2 determination；

Step 7, carrying out suing for peace by per section of friction loss obtains total friction loss, then by total friction loss and weight Force damage summation and obtain linear loss；

Wherein, screw pump lifts the linear loss pressure drop of viscous crude process, sees below formula, and along journey droop loss gravity is broadly divided into Loss ρ_LiquidG sin θs, friction lossAcceleration lossesThree parts；

Three part droop loss are analyzed, because its screw pump lifting process is at the uniform velocity process, the change of acceleration Change amount can be ignored substantially, so basic linear loss is from friction loss and gravity losses composition, such as following formula；

Step 8, the lift of the screw pump for obtaining linear loss and step 2 are compared, if linear loss is more than spiral shell Bar pump lift, i.e. screw pump can not be lifted；Conversely, screw pump can be used for lifting.

It is more preferably accurate in order to calculate, it is preferred embodiment that described per section depth is 100 meters.

Because due to the presence of geothermal gradient in lifting process, viscosity of crude rises with the decline of temperature, increase Flowing frictional resistance, needs to consider that formation temperature affects, i.e., described step 4 is specially：

A, oil reservoir depth is divided into into some sections,

B, the viscous kelvin relation of on-site measurement and geothermal gradient；

C, the temperature that per section is determined according to per section of depth；

D, the liquid viscosity for finally determining per section.

The specific embodiment of the present invention is further described with reference to embodiment, not therefore by present invention limit System is among described scope of embodiments.

Embodiment 1

The lifting crude oil ability judgement of screw pump is carried out by taking Xinjiang Oilfield block well as an example,

S100, the oil reservoir depth of the wellblock are 1600m, in the range of the lifting of conventional screw pump, then carry out screw pump production；

S200, oil reservoir oil well relevant parameter (such as table 2) for determining production development, and the viscous kelvin relation of on-site measurement and ground temperature ladder Degree；

Table 2

Daily output 3m³/ d can determine that lifting speed is 0.0176m/s, and oil reservoir depth can determine that raising for screw pump Journey 12.65MPA,

Inclination angle during S300, acquisition oil density, local gravity acceleration value and oilwell drilling with stratum, enters Row calculates gravity crushing；

S400, oil well is carried out into segmentation calculating, by viscosity of crude according to oil reservoir depth and the relation of viscosity of crude, per 100m A segmentation is done, the meansigma methodss of a viscosity of crude are done per 100m, the viscosity of crude in different well depth stages is pressed into gradient calculation, then Per section of viscosity is determined according to the viscous kelvin relation of on-site measurement and geothermal gradient；

S500, the viscosity by per section and following formula calculate per section of Reynolds number (result such as table 3)；

In formula：Re is Reynolds number, nondimensional number；v_mFor average speed, m/s；D is oil pumping shank diameter, m；D is that oil pipe is straight Footpath, m；ρ_lFor fluid density, kg/m³；μ_lFor liquid viscosity, mPas；

Table 3

Depth m	Average computation depth m	Temperature, DEG C	Viscosity, mPas	Re
					0	/	/	/	/
100	50	13.865	2.14502763	0.183698
					200	150	16.195	1.906094003	0.206725
300	250	18.525	1.68742108	0.233514
					400	350	20.855	1.488075339	0.264796
500	450	23.185	1.30712326	0.301453
					600	550	25.515	1.143631321	0.344549
700	650	27.845	0.996666001	0.395355
					800	750	30.175	0.86529378	0.455379
900	850	32.505	0.748581136	0.526378
					1000	950	34.835	0.645594548	0.610347
1100	1050	37.165	0.555400495	0.709464
					1200	1150	39.495	0.477065457	0.825959
1265	1232.5	41.41725	0.420704892	0.93661

S600, Moody chart is looked into again obtain corresponding resistance coefficient；Can be with by the Reynolds number of table 1 and frictional resistance corresponding relation Find out and belong to laminar flow, the resistance coefficient obtained by above-mentioned steps and following formula calculate per section of friction pressure gradient, then obtain every The friction loss (result such as table 4) of section；

In formula：τ_fFor friction pressure gradient, Pa/m；λ is resistance coefficient, zero dimension；v_lBe the pipeline section average pressure and Under mean temperature, the mean flow rate of liquid phase, m/s；ρ_lFor fluid density, kg/m³；D is tubing diameter, m；D is oil pumping shank diameter, m；

Table 4

S700, carrying out suing for peace by per section of friction loss obtains total friction loss, it can be seen from Table 4 that：Total rubs Resistance loss=per section friction loss and=0.544MPa；Again because along journey droop loss=friction loss+gravity losses+acceleration Degree loss, because its screw pump lifting process is at the uniform velocity process, the variable quantity of acceleration can be ignored substantially, so basic along journey Loss is constituted from friction loss and gravity losses；So linear loss=friction loss+gravity losses+acceleration losses= 11.93MPa；

S800, the lift 12.65MPA of the screw pump that step S200 is obtained and the calculated linear loss of step S700 11.93MPa is judged that the lift 12.65MPA of screw pump is more than linear loss 11.93MPa, then screw rod pump lift can be Meet the linear loss, can lift.

Claims (2)

1. the pre-judging method that a kind of Shallow Heavy Oil Reservoir single-phase flow screw pump is lifted, it is characterised in that the method includes following step Suddenly：

Step one, the oil well of selection Suitable depth carry out screw pump production, and the wherein depth of oil well is less than or equal to 1800 meters；

Step 2, determine the oil reservoir oil well relevant parameter of production development, and determine the lift of screw pump, lifting speed, the oil Hiding oil well relevant parameter includes oil reservoir depth, the daily output, tubing diameter, oil pumping shank diameter, fluid density, shaft bottom viscosity of crude；

Inclination angle during step 3, acquisition oil density, local gravity acceleration value and oilwell drilling with stratum, is carried out Calculate gravity crushing；

Step 4, oil well is carried out into segmentation calculating, per section of liquid viscosity is calculated respectively；

Step 5, the liquid viscosity by per section and following formula calculate per section of Reynolds number, then look into the corresponding resistance of Moody chart acquisition Force coefficient；

$\mathrm{Re}=\frac{(D-d)v_m{\mathrm{\ρ}}_l}{{\mathrm{\μ}}_l}$

In formula：Re is Reynolds number, nondimensional number；v_mFor average speed, m/s；D is oil pumping shank diameter, m；D is tubing diameter, m；ρ_l For fluid density, kg/m³；μ_lFor liquid viscosity, mPas；

Step 6, the resistance coefficient obtained by above-mentioned steps and following formula calculate per section of friction pressure gradient, then obtain per section Friction loss；

${\mathrm{\τ}}_f=\frac{{\mathrm{\λ\ρ}}_l{v}_l^2}{2(D-d)}$

In formula：τ_fFor friction pressure gradient, Pa/m；λ is resistance coefficient, zero dimension；v_lIt is in the average pressure of the pipeline section and average At a temperature of, the mean flow rate of liquid phase, m/s；ρ_lFor fluid density, kg/m³；D is tubing diameter, m；D is oil pumping shank diameter, m；

Step 7, carrying out suing for peace by per section of friction loss obtains total friction loss, then by total friction loss and gravity pressure Damage summation and obtain linear loss；

Step 8, the lift of the screw pump for obtaining linear loss and step 2 are compared, if linear loss is more than screw pump Lift, i.e. screw pump can not be lifted；Conversely, screw pump can be used for lifting.

2. the pre-judging method that a kind of Shallow Heavy Oil Reservoir single-phase flow screw pump according to claim 1 is lifted, its feature exists In the step 4 is specially：

A, oil reservoir depth is divided into into some sections,

B, the viscous kelvin relation of on-site measurement and geothermal gradient；

C, the temperature that per section is determined according to per section of depth；

D, the liquid viscosity for finally determining per section.