An offshore platform polymer strong dispersion liquid preparation module optimization design method

Abstract

This invention discloses an optimized design method for a polymer-based high-performance dispersion preparation module for offshore platform oil recovery. The method includes: constructing a small-scale indoor high-performance dispersion experimental device; conducting indoor evaluation experiments to optimize the preparation effect of the high-performance dispersion model and obtain the optimal design parameters of the small-scale high-performance dispersion module; establishing an equivalent centrifugal force mathematical model, using the equivalent centrifugal force as a benchmark, and by generating the same centrifugal force at the outermost edge of the packing material in both the small-scale and existing high-performance dispersion modules, industrial-scale scaling up the optimal design parameters of the small-scale high-performance dispersion module, thereby establishing a quantitative relationship between the small-scale and existing high-performance dispersion modules; and determining the optimal design parameters of the industrial-scale high-performance dispersion module based on the optimal design parameters of the small-scale high-performance dispersion module and the quantitative relationship between the small-scale and existing high-performance dispersion modules, thus providing guidance for the optimized design of the industrial-scale high-performance dispersion module.

Description

Technical Field

[0001] This invention belongs to the field of petroleum engineering technology, and more specifically, it relates to an optimized design method for a polymer strong dispersion and preparation module for offshore platform oil recovery. Background Technology

[0002] In the field of oil extraction, polymer flooding is a key technology for improving oil recovery. Its technical principle is to inject a water-soluble polymer solution with a certain viscosity into the oil reservoir to improve the mobility ratio of the displacement fluid to the crude oil, expand the swept volume, and thus effectively drive the crude oil to achieve a significant improvement in recovery.

[0003] In recent years, offshore oil exploration and development has become an important successor area for increasing oil and gas reserves and production in my country, and polymer flooding technology has been gradually promoted and applied to offshore oil fields. However, the special operating environment of offshore platforms has placed stringent requirements on the supporting processes for polymer flooding: offshore platforms have extremely limited space resources and strict upper limits on equipment load-bearing capacity. The polymer curing tank preparation process widely used in traditional onshore oil fields has inherent defects such as large footprint, bulky equipment, and long polymer dissolution time, which have created a prominent contradiction with the application conditions of offshore platforms and seriously restricted the large-scale promotion and application of polymer flooding technology in offshore oil fields.

[0004] To overcome the aforementioned technical bottlenecks, existing technologies have developed an industrial-scale polymer rapid dissolution device (hereinafter referred to as the "rapid dissolution device"). This device employs a combined process of forced stretching and strong dispersion, which can significantly shorten the polymer dissolution time and substantially reduce the equipment volume. Among them, the strong dispersion module is the core functional component of the rapid dissolution device. Its internal packing bed structure design and the selection of operating process parameters directly determine the dispersion effect of polymer particles, solution uniformity, and final solution quality. Currently, this rapid dissolving unit has been tested in some offshore oilfields in my country, and the overall solution preparation effect basically meets the requirements of field production. However, the following technical shortcomings have been exposed in actual application: First, the viscosity retention rate of the polymer solution prepared by the rapid dissolving unit is relatively low, only about 90% of that of the conventional curing tank process, which to some extent reduces the actual oil displacement effect of polymer flooding. Second, the unit is not adaptable to different types of polymers. When using different systems such as linear polymers and associative polymers, it is necessary to repeatedly adjust the process parameters to achieve a qualified solution preparation effect, which increases the complexity and difficulty of field operation. Third, when preparing high-concentration polymers (>5000ppm), due to the high viscosity of the polymer, the flow capacity through the strong dispersion module is poor and slow, which makes the strong dispersion module prone to clogging, causing liquid accumulation, overflow or overflow, affecting the continuous operation of the equipment. Therefore, in order to further improve the solution preparation effect and processing capacity of the rapid dissolving unit, it is urgent to carry out systematic optimization design of the structure and process parameters of the strong dispersion module.

[0005] Currently, the design and development of such large-scale industrial high-power dispersion modules mainly relies on three methods: empirical methods, numerical simulation methods, and large-scale physical simulation experiments. Empirical methods primarily depend on the practical experience of engineers to qualitatively judge and design the structural parameters and operating processes of the dispersion bed. The design results are highly dependent on the designer's personal experience and lack scientific quantitative guidance, making it difficult to guarantee the consistency and reliability of the design results. Numerical simulation is a commonly used method for studying dispersion processes, but existing simulation methods typically simplify polymers to solid particles, judging the dispersion and dissolution effect only by simulating the macroscopic dispersion degree of particles in water. This fails to accurately consider the actual physical dissolution processes such as the swelling and molecular chain extension of polymer particles upon contact with water, leading to significant deviations between simulation results and the actual dissolution process, and the simulation accuracy is insufficient to meet engineering design requirements. Large-scale physical simulation experiments can realistically reproduce the entire dispersion and dissolution process of polymers and are a reliable means of verifying design schemes. However, the cost and time required for a single experiment are high, and it is impossible to systematically and comprehensively study the influence of different structural and process parameters.

[0006] In summary, existing design methods for powerful distributed modules generally suffer from prominent problems such as insufficient scientific rigor, poor design accuracy, low experimental efficiency, and high R&D costs. There is an urgent need to develop a scientific design method that is highly efficient, accurate, and low-cost to guide the optimized design of powerful distributed industrial modules. Summary of the Invention

[0007] This invention aims to address the technical problems of insufficient scientific rigor, poor design accuracy, low experimental efficiency, and high R&D costs in existing high-strength dispersion module design methods. It provides an optimized design method for polymer high-strength dispersion preparation modules for offshore platform oil recovery. By combining indoor experiments and mathematical models, it achieves a scientific and precise design of the high-strength dispersion module, improves the viscosity retention rate and flow capacity of the polymer solution, enhances the adaptability of the device to different types of polymers, and reduces R&D costs and time.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: an optimized design method for a polymer high-strength dispersion preparation module for offshore platform oil recovery, comprising the following steps:

[0009] A small-scale indoor high-strength dispersion experimental device was constructed, including a swelling solution preparation module, a polymer injection pump, a small-scale high-strength dispersion module, a stepper motor, an online sampler, and a viscometer. The small-scale high-strength dispersion module comprises a high-strength dispersion shell consisting of an inner grid tube, an outer grid tube, and a base plate, and a mandrel disposed within the high-strength dispersion shell. A dispersion bed mesh is placed between the inner and outer grid tubes as packing material. The mandrel is driven by the stepper motor, allowing for adjustable rotation speed. The swelling solution preparation module is connected to the small-scale high-strength dispersion module via the polymer injection pump, and the small-scale high-strength dispersion module is connected to the viscometer via the online sampler. Indoor evaluation experiments were conducted to optimize the liquid preparation effect of the strong dispersion model. The effects of different key design parameters on viscosity retention, dispersion and dissolution degree and transit time were analyzed and studied to obtain the optimal design parameters for the small strong dispersion module. An equivalent centrifugal force mathematical model is established. Based on the equivalent centrifugal force, the same centrifugal force is generated at the outermost edge of the packing by making the small strong dispersion module and the existing strong dispersion module generate the same centrifugal force. In this way, the optimal design parameters of the small strong dispersion module are scaled up in an industrial manner, and a quantitative relationship between the small strong dispersion module and the existing strong dispersion module is established. Based on the optimal design parameters of the small-scale high-power dispersion module and the quantitative relationship between the small-scale high-power dispersion module and the existing high-power dispersion module, the optimal design parameters of the industrial-scale high-power dispersion module are determined.

[0010] As a preferred option, the following steps are also included: Based on the optimal design parameters of the industrial-scale high-power dispersion module, the industrial-scale high-power dispersion module is manufactured. The manufactured industrial-scale high-power dispersion module is installed in the polymer preparation system of the offshore platform, and liquid preparation experiments are conducted to verify and evaluate the design effect.

[0011] As a preferred option, the specific procedure for the indoor evaluation experiment is as follows: First, a polymer solution in a swollen state is prepared using a swelling preparation module. Then, it is pumped into a small, high-power dispersion module via a polymer injection pump. The solution is then strongly dispersed by centrifugal force generated by the high-speed rotation of the small, high-power dispersion module. The dispersed solution is sampled by an online sampler and then sent to a viscometer to measure the viscosity retention rate.

[0012] Preferably, the viscosity retention rate is the ratio of the viscosity measured online after strong dispersion of the polymer to the reference viscosity, calculated by the following formula:

[0013] In the formula, Viscosity retention rate; For line sampling to measure viscosity; The reference viscosity is 1.

[0014] Preferably, the method for measuring the degree of dispersion and dissolution is as follows: First, take 100g of the polymer solution prepared by the small high-power dispersion module 3 and pour it onto a 100-mesh sieve. Filter the solution using gravity, then weigh the polymer residue on the sieve, and finally calculate the degree of dispersion and dissolution using the following formula:

[0015] In the formula, To the degree of dispersion and dissolution; This refers to the mass of polymer residues.

[0016] Preferably, the mathematical model of the equivalent centrifugal force is expressed as F=mω²r, where m is the unit fluid mass in the powerful dispersion module, ω is the rotational speed of the powerful dispersion module, and r is the radius of the outer grid tube.

[0017] Preferably, the quantitative relationship between the small high-power dispersion module and the existing high-power dispersion module is m. s ω s ²r s =m b ω b ²r b , where m s For the unit fluid mass in a small, high-power dispersion module, ω s For the rotational speed of the small, high-power dispersion module, r s The radius of the outer grid tube in the small high-power dispersion module is m. b For the unit fluid mass in the existing high-power dispersion module, ω b For the rotational speed of the existing high-power dispersion module, r b The radius of the outer grid tube in the existing high-strength dispersion module.

[0018] The present invention has the following advantages due to the adoption of the above technical solutions: 1. Improved design scientificity and accuracy: This invention solves the problems of lack of scientific guidance in empirical methods, insufficient accuracy in numerical simulation methods, and low efficiency in large-scale experimental methods in existing technologies by combining indoor experiments and mathematical models, and realizes the scientific and precise design of powerful distributed modules.

[0019] 2. Improved polymer solution viscosity retention rate: The industrial-grade high-strength dispersion module optimized by the method of this invention increases the polymer solution viscosity retention rate from 90% to 94%, significantly improving the actual oil displacement effect of polymer flooding. Moreover, the equipment operates smoothly without liquid accumulation or overflow, and has strong flow capacity.

[0020] 3. Enhanced equipment adaptability: The method of this invention can be optimized for different types of polymers (such as linear polymers, associative polymers, etc.), which improves the adaptability of the equipment to different types of polymers and reduces the need for repeated adjustment of process parameters during on-site operation.

[0021] 4. Reduced R&D costs and cycle: This invention significantly reduces the trial-and-error costs of large-scale physical simulation experiments and shortens the R&D cycle by combining small-scale indoor experiments with mathematical models, providing reliable theoretical guidance and scientific basis for the optimized design of powerful decentralized industrial modules. Attached Figure Description

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a schematic diagram of the structure of a small-scale indoor high-power dispersion experimental device provided in an embodiment of the present invention; Figure 2 This is a structural diagram of a forced stretching module provided in an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0024] The present invention provides an optimized design method for polymer high-strength dispersion modules for offshore platform oil recovery, comprising: constructing a small-scale indoor high-strength dispersion experimental device; conducting indoor evaluation experiments to optimize the liquid preparation effect of the high-strength dispersion model and obtain the optimal design parameters of the small-scale high-strength dispersion module; establishing an equivalent centrifugal force mathematical model, using the equivalent centrifugal force as a benchmark, and by generating the same centrifugal force at the outermost edge of the packing in both the small-scale high-strength dispersion module and existing high-strength dispersion modules, thereby industrial-scale scaling up the optimal design parameters of the small-scale high-strength dispersion module, and establishing a quantitative relationship between the small-scale high-strength dispersion module and existing high-strength dispersion modules; and determining the optimal design parameters of the industrial-scale high-strength dispersion module based on the optimal design parameters of the small-scale high-strength dispersion module and the quantitative relationship between the small-scale high-strength dispersion module and existing high-strength dispersion modules, thereby providing guidance for the optimized design of industrial-scale high-strength dispersion modules.

[0025] The following is a detailed description, with reference to the accompanying drawings, of the optimized design method for a polymer strong dispersion and preparation module for offshore platform oil recovery provided by the present invention.

[0026] This invention provides an optimized design method for a polymer high-strength dispersion preparation module for offshore platform oil recovery, comprising the following steps: S100. Please refer to Figure 1 An indoor small-scale high-power dispersion experimental device was constructed, including a swelling and solution preparation module 1, a polymer injection pump 2, a small-scale high-power dispersion module 3, a stepper motor 4, an online sampler 5, and a viscosity meter 6.

[0027] Please see Figure 2The small, high-power dispersion module 3 includes a high-power dispersion shell composed of an inner grid tube 31, an outer grid tube 32, and a base plate 33, and a mandrel 34 disposed within the high-power dispersion shell. A dispersion bed wire mesh (not shown in the figure) is placed between the inner grid tube 31 and the outer grid tube 32 as a packing material. The mandrel 34 is driven by a stepper motor 4 to achieve adjustable speed. The swelling solution preparation module 1 is connected to the small, high-power dispersion module 3 via a polymer injection pump 2. The small, high-power dispersion module 3 is connected to a viscosity meter 6 via an online sampler 5. A stopwatch is used to time the time it takes for the polymer to pass through the high-power dispersion module. The shorter the time, the better the flow capacity of the high-power dispersion module.

[0028] S200. Conduct an indoor evaluation experiment to optimize the liquid preparation effect of the strong dispersion model. The polymer concentration is 10,000 ppm. Analyze the effects of different key design parameters (number of packing layers, rotation speed) on viscosity retention, dispersion and dissolution degree and passage time (time for polymer to pass through small strong dispersion module 3 is timed by a stopwatch) to obtain the optimal design parameters of small strong dispersion module 3.

[0029]

[0030] Based on the above experimental results, the optimal design parameters for the small, high-performance dispersion module 3, determined through indoor experiments, are: 7 filler layers (corresponding to a filler thickness of 4 cm) and a rotation speed of 1200 rpm. Under these conditions, the viscosity retention rate reaches 95%, the dispersion and dissolution rate reaches 100%, and the shortest transit time is 8.4 s.

[0031] In the above embodiments, preferably, the viscosity retention rate is the ratio of the viscosity measured online after strong dispersion of the polymer to the reference viscosity, and is calculated by the following formula:

[0032] In the formula, Viscosity retention rate; For line sampling to measure viscosity; The reference viscosity is 1.

[0033] In the above embodiments, preferably, the method for measuring the degree of dispersion and dissolution is as follows: First, 100g of the polymer solution prepared by the small high-power dispersion module 3 is poured onto a 100-mesh sieve and filtered by gravity. Then, the polymer residue on the sieve is weighed, and finally, the degree of dispersion and dissolution is calculated using the following formula:

[0034] In the formula, To the degree of dispersion and dissolution; This refers to the mass of polymer residues.

[0035] S300. Establish an equivalent centrifugal force mathematical model. Based on the equivalent centrifugal force, generate the same centrifugal force at the outermost edge of the packing by making the small strong dispersion module 3 and the existing strong dispersion module (i.e., the strong dispersion system in Chinese invention patent application CN115888519A) generate the same centrifugal force. In this way, the optimal design parameters of the small strong dispersion module 3 are scaled up in an industrial manner, and then a quantitative relationship between the small strong dispersion module 3 and the existing strong dispersion module is established.

[0036] S400. Based on the optimal design parameters of the small high-power dispersion module 3 and the quantitative relationship between the small high-power dispersion module and the existing high-power dispersion module, determine the optimal design parameters of the industrial high-power dispersion module, including the number of packing layers and the rotation speed.

[0037] In the above embodiments, preferably, the method further includes step S500: manufacturing an industrial-scale large-scale high-power dispersion module according to the design parameters of the industrial-scale high-power dispersion module, installing the manufactured industrial-scale large-scale high-power dispersion module in the polymer formulation system of the offshore platform, and conducting liquid preparation experiments to verify and evaluate the design effect.

[0038] In the above embodiments, preferably, in step S200, the process of the indoor evaluation experiment is as follows: First, a polymer solution in a swollen state is prepared by the swelling solution preparation module 1, and then it is transported to the small high-power dispersion module 3 by the polymer injection pump 2. The solution is strongly dispersed by the centrifugal force generated by the high-speed rotation of the small high-power dispersion module 3. The dispersed solution is sampled by the online sampler 5 and then sent to the viscosity meter 6 for viscosity retention rate measurement.

[0039] In the above embodiments, preferably, the mathematical model of equivalent centrifugal force is expressed as F=mω²r, where m is the unit fluid mass, ω is the rotational speed of the powerful dispersion module, and r is the radius of the outer grid tube.

[0040] In the above embodiments, preferably, the quantitative relationship between the small high-power dispersion module 3 and the existing high-power dispersion module is m. s ω s ²r s =m b ω b ²r b , where m s For the unit fluid mass in the small, powerful dispersion module 3, ω s For the rotational speed of the small, high-power dispersion module 3, r s The radius of the outer grid tube in the small high-power dispersion module 3 is m. b For the unit fluid mass in the existing high-power dispersion module, ω b For the rotational speed of the existing high-power dispersion module, r bThe radius of the outer grid tube in the existing high-strength dispersion module.

[0041] Based on the experimental optimization results, ω s =1200rpm, r s =4cm (7 layers of filler), m s， m b All values ​​are unit mass flow rates, taken as 1 kg / s. Considering the actual operating conditions of existing large-scale industrial plants in the field, ω b =600rpm, therefore r can be calculated. b =16cm, meaning the optimal filler radius and thickness for the existing high-strength dispersion module is 16cm.

[0042] Based on the above design calculations, the thickness of the existing high-strength dispersing filler was re-optimized and processed, and a liquid preparation experiment was conducted. After structural optimization, the viscosity retention rate of the prepared liquid increased from 90% to 94%, and no liquid accumulation or overflow occurred during equipment operation, indicating that the polymer fluid has good flow performance in the high-strength dispersing module. Therefore, the accuracy, scientificity, and reliability of the high-strength dispersing module design method proposed in this invention are proven, and this method can be used to guide the design and processing of subsequent high-strength dispersing industrial modules.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An optimized design method for a polymer high-strength dispersion preparation module for offshore platform oil recovery, characterized in that, Includes the following steps: A small-scale indoor high-strength dispersion experimental device was constructed, including a swelling solution preparation module, a polymer injection pump, a small-scale high-strength dispersion module, a stepper motor, an online sampler, and a viscometer. The small-scale high-strength dispersion module comprises a high-strength dispersion shell consisting of an inner grid tube, an outer grid tube, and a base plate, and a mandrel disposed within the high-strength dispersion shell. A dispersion bed mesh is placed between the inner and outer grid tubes as packing material. The mandrel is driven by the stepper motor, allowing for adjustable rotation speed. The swelling solution preparation module is connected to the small-scale high-strength dispersion module via the polymer injection pump, and the small-scale high-strength dispersion module is connected to the viscometer via the online sampler. Indoor evaluation experiments were conducted to optimize the liquid preparation effect of the strong dispersion model. The effects of different key design parameters on viscosity retention, dispersion and dissolution degree and transit time were analyzed and studied to obtain the optimal design parameters for the small strong dispersion module. An equivalent centrifugal force mathematical model is established. Based on the equivalent centrifugal force, the same centrifugal force is generated at the outermost edge of the packing by making the small strong dispersion module and the existing strong dispersion module generate the same centrifugal force. In this way, the optimal design parameters of the small strong dispersion module are scaled up in an industrial manner, and a quantitative relationship between the small strong dispersion module and the existing strong dispersion module is established. Based on the optimal design parameters of the small-scale high-power dispersion module and the quantitative relationship between the small-scale high-power dispersion module and the existing high-power dispersion module, the optimal design parameters of the industrial-scale high-power dispersion module are determined.

2. The optimized design method for a polymer high-dispersion liquid preparation module for offshore platform oil recovery according to claim 1, characterized in that, It also includes the following steps: Based on the optimal design parameters of the industrial-scale high-power dispersion module, the industrial-scale high-power dispersion module is manufactured. The manufactured industrial-scale high-power dispersion module is installed in the polymer preparation system of the offshore platform, and liquid preparation experiments are conducted to verify and evaluate the design effect.

3. The optimized design method for a polymer high-dispersion liquid preparation module for offshore platform oil recovery according to claim 1, characterized in that, The specific procedure for the indoor evaluation experiment is as follows: First, a polymer solution in a swollen state is prepared using a swelling preparation module. Then, it is pumped into a small, high-power dispersion module via a polymer injection pump. The solution is then strongly dispersed by centrifugal force generated by the high-speed rotation of the small, high-power dispersion module. The dispersed solution is sampled by an online sampler and then sent to a viscometer to measure the viscosity retention rate.

4. The optimized design method for a polymer high-dispersion liquid preparation module for offshore platform oil recovery according to claim 1, characterized in that, The viscosity retention rate is the ratio of the viscosity measured online after strong dispersion of the polymer to the reference viscosity, and is calculated by the following formula: In the formula, Viscosity retention rate; For line sampling to measure viscosity; The reference viscosity is 1.

5. The optimized design method for a polymer high-dispersion liquid preparation module for offshore platform oil recovery according to claim 1, characterized in that, The method for measuring the degree of dispersion and dissolution is as follows: First, take 100g of the polymer solution prepared by the small high-power dispersion module 3 and pour it onto a 100-mesh sieve. Filter the solution using gravity. Then, weigh the polymer residue on the sieve. Finally, calculate the degree of dispersion and dissolution using the following formula: In the formula, To the degree of dispersion and dissolution; This refers to the mass of polymer residues.

6. The optimized design method for a polymer high-dispersion liquid preparation module for offshore platform oil recovery according to claim 1, characterized in that, The mathematical model of the equivalent centrifugal force is expressed as F=mω²r, where m is the unit fluid mass in the strong dispersion module, ω is the rotational speed of the strong dispersion module, and r is the radius of the outer grid tube.

7. The optimized design method for a polymer high-dispersion liquid preparation module for offshore platform oil recovery according to claim 6, characterized in that, The quantitative relationship between the small-scale high-power dispersion module and the existing high-power dispersion module is m. s ω s ²r s =m b ω b ²r b , where m s For the unit fluid mass in a small, high-power dispersion module, ω s For the rotational speed of the small, high-power dispersion module, r s The radius of the outer grid tube in the small high-power dispersion module is m. b For the unit fluid mass in the existing high-power dispersion module, ω b For the rotational speed of the existing high-power dispersion module, r b The radius of the outer grid tube in the existing high-strength dispersion module.

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