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CN-122014186-A - Adaptive control method for electric heating power of thickened oil exploitation based on underground temperature feedback

CN122014186ACN 122014186 ACN122014186 ACN 122014186ACN-122014186-A

Abstract

The invention discloses an underground temperature feedback-based electric heating power self-adaptive control method for thick oil exploitation, in particular to the field of thick oil exploitation intelligent control, which comprises the steps of dividing a shaft heating section according to an adjustable interval of 0.5-2 m, synchronously acquiring combined data through a Pt100 sensor group and a viscosity sensor in annular layout, and generating a temperature characteristic vector and a viscosity time sequence; the method comprises the steps of constructing a dynamic weight matrix through fuzzy similarity matching, generating temperature control compensation gain by combining with the curvature of a viscous Wen Nige curve, outputting a segmented power instruction by adopting a main and auxiliary coil cooperation and neighbor compensation strategy, modifying the weight matrix in a closed loop mode through a PI algorithm, and updating the instruction in an iterative mode until the viscosity is stabilized at 1500-3000mPa s.

Inventors

  • SUN JIANXIN
  • LIU YINGHAO
  • CHEN YUE

Assignees

  • 东营市沃格艾迪石油技术有限公司

Dates

Publication Date
20260512
Application Date
20260130

Claims (7)

  1. 1. The adaptive control method for the electric heating power of the heavy oil exploitation based on the underground temperature feedback is characterized by comprising the following steps: A1, dividing N independent heating sections in the longitudinal direction of a shaft at intervals of 0.5-2 m, acquiring temperature data by each section through a Pt100 platinum thermal resistance sensor group in ring topology layout, synchronously acquiring thick oil viscosity-temperature combination data of each section, and generating a temperature characteristic vector and viscosity time sequence; A2, carrying out fuzzy similarity matching on the temperature characteristic vector and a preset heat flow distribution mode library, calculating thermal inertia unbalance coefficients of each section, and constructing a dynamic weight matrix, wherein matrix element values represent thermal inertia overload, underload and steady state states; A3, curve fitting is carried out on the viscosity-temperature combination data, a curvature value of a fitting curve corresponding to the current temperature is calculated, and temperature control compensation gain is dynamically generated by combining the thermal inertia unbalance coefficient; a4, outputting a sectional power regulation instruction based on the dynamic weight matrix and the temperature control compensation gain, preferentially calling the redundant power of the main coil and the auxiliary coil, and starting the compensation heating of the adjacent section when the viscosity improvement rate is less than a preset standard; and A5, collecting the viscosity data of the heated thickened oil, correcting the dynamic weight matrix through a proportional-integral algorithm, and iteratively updating the sectional power regulation instruction until the viscosity enters a preset steady-state range.
  2. 2. The adaptive control method for electric heating power of thick oil exploitation based on underground temperature feedback according to claim 1, wherein in A1, in the longitudinal direction of thick oil exploitation shaft, N independent heating sections are uniformly divided according to adjustable intervals of 0.5-2 m by combining underground geologic layering characteristics, thick oil viscosity distribution rules and heating energy efficiency optimization principles, wherein the lower-viscosity area of shallow thick oil is divided at intervals of 1.5-2 m, and the deep-layer high-viscosity area is divided at encryption intervals of 0.5-1 m; Each independent heating section is provided with a Pt100 platinum thermal resistance sensor group in ring topology layout, after data acquisition is completed, temperature data of each section are preprocessed, abnormal fluctuation values are removed and smooth filtering is carried out, core parameters of the sections are extracted, temperature feature vectors representing distribution features of the temperature fields of the sections are constructed, viscosity data are ordered according to time sequence, and a continuous viscosity time sequence is formed.
  3. 3. The method for adaptively controlling electric heating power of heavy oil exploitation based on downhole temperature feedback according to claim 1, wherein in A2, a ground control center is pre-stored with a 'preset heat flow distribution pattern library' constructed based on a geological model and historical production data, in real-time control, a system performs fuzzy similarity matching calculation on actual temperature feature vectors of N sections currently collected and constructed and template vectors in the pattern library, a comprehensive similarity measurement algorithm combining weighted Euclidean distance and included angle cosine is adopted in the matching process, a fuzzy membership function is introduced to process uncertainty and transition state of a downhole temperature field, the system recognizes which preset pattern is closest to the current overall temperature field through fuzzy similarity matching, and calculates that each independent heating section i is relative to an optimal matching pattern Degree of state deviation of corresponding section ; Based on the degree of deviation of the state The rate of change of the zone temperature The system further calculates a thermal inertia imbalance coefficient The thermal inertia imbalance coefficient is calculated by the formula: , Wherein, the And For the weight coefficient calibrated according to the stratum thermophysical property, Expressed as the desired rate of temperature change for the segment in this mode.
  4. 4. The adaptive control method for the electric heating power of the heavy oil exploitation based on the underground temperature feedback of claim 1 is characterized in that in A3, a ground control center processes viscosity-temperature combination data synchronously acquired by each independent heating section i in real time, firstly, an Arrhenius type function is adopted to carry out least square curve fitting, a localized viscosity-temperature relation model of the section under the current working condition is established, the fitting model is an improved Andred equation, and the calculation method specifically comprises the following steps: , Wherein, the Represented as a viscosity function of the i-th segment, Represented by the proportionality constant(s), Represented as an activation energy class parameter, Denoted as offset correction term, T denoted as temperature; System calculation at current real-time temperature The calculating method of the curvature value of the fitting curve specifically comprises the following steps: , Wherein, the Expressed as a curvature value, Represented as a fitting function With respect to the first derivative of the temperature, Represented as a fitting function Second derivative with respect to temperature.
  5. 5. The adaptive control method of electric heating power for heavy oil recovery based on downhole temperature feedback of claim 1, wherein in A4, based on the dynamic weight matrix constructed in the foregoing and the temperature control compensation gain generated in real time, basic power regulation and control instruction calculation of each independent heating section is completed, namely, power distribution is precisely matched with the thermal inertia state and viscosity temperature sensitivity characteristics of the section; In the power execution level, a main and auxiliary coils cooperative working mode is adopted, each heating section is provided with a group of main heating coils and two groups of auxiliary heating coils, the main coils bear basic heating loads, the auxiliary coils serve as redundant capacity for standby, after a basic power regulation instruction is issued, the system detects the current load rate of the main coils, if the load rate of the main coils is lower than 70%, the current load rate is preferably regulated by the redundant capacity of the main coils, if the load rate of the main coils is higher than 85%, and the basic power still does not meet the regulation requirement, a group of auxiliary coils are started, energy supplementing is carried out through power superposition of the main coils and the auxiliary coils, and meanwhile, the working temperature and the insulation state of the coils are monitored in real time.
  6. 6. The adaptive control method for electric heating power of heavy oil recovery based on downhole temperature feedback according to claim 5, wherein the adjacent section compensation heating is required to follow a thermal balance constraint and a safety boundary, the adjacent section which is closest to the target section in axial distance and is in a steady state in current thermal inertia is selected first, the temperature difference between the target section and the adjacent section is monitored simultaneously in real time, the viscosity improvement rate change is tracked in the compensation heating process, when the viscosity improvement rate reaches a preset standard or the viscosity of the target section enters a steady state range, the compensation power of the adjacent section is reduced until compensation is stopped completely, and the independent heating state of each section is restored.
  7. 7. The adaptive control method of electric heating power for heavy oil recovery based on downhole temperature feedback according to claim 1, wherein in A5, after main and auxiliary coil heating and adjacent section compensation heating are performed, the system synchronously collects the heavy oil viscosity data of each heating section according to a preset collection period, the collection process is aligned with the temperature data collection and maintains time sequence, the collected viscosity data is subjected to validity verification, abnormal values caused by fluid disturbance and instantaneous drift of a sensor are removed, and meanwhile, the data is compared with the initial viscosity value before power adjustment, so that the actual effect of power regulation is primarily judged; Based on the verified effective viscosity data, a proportional-integral algorithm is introduced to conduct closed-loop correction on the dynamic weight matrix, the correction of the PI algorithm firstly calculates absolute deviation values of real-time viscosity and preset steady-state viscosity, a proportional link timely outputs correction values according to the deviation values to adjust the weight matrix, an integral link conducts time integral operation on the deviation values, and in the correction process, the proportional coefficient and the integral coefficient of the PI algorithm are required to be dynamically adapted according to the thick oil viscosity interval.

Description

Adaptive control method for electric heating power of thickened oil exploitation based on underground temperature feedback Technical Field The invention relates to the technical field of intelligent control of thickened oil exploitation, in particular to an adaptive control method of electric heating power of thickened oil exploitation based on underground temperature feedback. Background Because of high viscosity and poor fluidity, the thick oil needs to increase the temperature of a shaft by an electric heating technology to reduce the viscosity, thereby ensuring the lifting efficiency. The existing electric heating control technology mainly has the following defects: the temperature monitoring surface adopts single-point or local temperature measurement, can not capture the change of the underground three-dimensional temperature gradient, and is easy to cause local overheating coking or underheating viscosity; the adjustment response is lagged, namely the adjustment response is controlled by depending on fixed parameters, the adaptability to the nonlinear change of the viscosity of the thick oil along with the temperature is poor, and the compensation gain lacks dynamic adjustment capability; The energy efficiency is not utilized enough, the power distribution depends on single regulation of the main coil, the redundant capacity is not fully utilized, and no adjacent cell cooperative compensation mechanism exists, so that the energy waste is caused. For example, the oil field electric heating vacuum phase change heating furnace disclosed in Chinese patent CN210135689U can monitor inlet and outlet temperatures and adjust power according to temperature difference, but does not consider viscosity dynamic change and thermal inertia influence, and has limited adjusting precision. The intelligent control system of the Chinese patent CN202220172215.1 relies on manual setting of the power limit value, and lacks theoretical optimization basis. Therefore, development of an adaptive control method based on multidimensional temperature feedback is needed to improve the temperature control precision and energy efficiency of heavy oil exploitation. Disclosure of Invention In order to overcome the above-mentioned drawbacks of the prior art, embodiments of the present invention provide a method for adaptively controlling electric heating power for heavy oil recovery based on downhole temperature feedback, so as to solve the problems set forth in the above-mentioned background art. In order to achieve the above purpose, the present invention provides the following technical solutions: A1, dividing N independent heating sections in the longitudinal direction of a shaft at intervals of 0.5-2 m, acquiring temperature data by each section through a Pt100 platinum thermal resistance sensor group in ring topology layout, synchronously acquiring thick oil viscosity-temperature combination data of each section, and generating a temperature characteristic vector and viscosity time sequence; A2, carrying out fuzzy similarity matching on the temperature characteristic vector and a preset heat flow distribution mode library, calculating thermal inertia unbalance coefficients of each section, and constructing a dynamic weight matrix, wherein matrix element values represent thermal inertia overload, underload and steady state states; A3, curve fitting is carried out on the viscosity-temperature combination data, a curvature value of a fitting curve corresponding to the current temperature is calculated, and temperature control compensation gain is dynamically generated by combining the thermal inertia unbalance coefficient; a4, outputting a sectional power regulation instruction based on the dynamic weight matrix and the temperature control compensation gain, preferentially calling the redundant power of the main coil and the auxiliary coil, and starting the compensation heating of the adjacent section when the viscosity improvement rate is less than a preset standard; and A5, collecting the viscosity data of the heated thickened oil, correcting the dynamic weight matrix through a proportional-integral algorithm, and iteratively updating the sectional power regulation instruction until the viscosity enters a preset steady-state range. Preferably, in the A1, in the longitudinal direction of the thick oil exploitation shaft, N independent heating sections are uniformly divided according to adjustable intervals of 0.5-2 m by combining with underground geological stratification characteristics, thick oil viscosity distribution rules and optimal heating energy efficiency principles, wherein the shallow thick oil viscosity lower area is divided at intervals of 1.5-2 m, and the deep high viscosity area is divided at intervals of 0.5-1 m, so that accurate coverage of the key viscosity sensitive sections is ensured; Each independent heating section is provided with a Pt100 platinum thermal resistance sensor group in ring topology layout, the s