CN-121803199-B - Sand-filling prevention well completion optimization construction method for ultra-deep water ultra-shallow gas low-temperature reservoir coating sand

CN121803199BCN 121803199 BCN121803199 BCN 121803199BCN-121803199-B

Abstract

The invention belongs to the technical field of oil and gas engineering, and particularly relates to an ultra-deep water ultra-shallow gas low-temperature reservoir coating sand filling sand prevention well completion optimization construction method. The method comprises the steps of S1, a screen pipe coated sand circulation filling construction method for ensuring coated sand consolidation of an ultra-deep ultra-shallow gas low-temperature reservoir, S2, a near-well reservoir temperature and liquid amount design method in a heat treatment reservoir stage before circulation filling of the ultra-deep ultra-shallow gas low-temperature reservoir, and S3, an ultra-deep ultra-shallow gas low-temperature reservoir heat liquid coated sand gravel filling and displacement liquid amount design method. The invention can smoothly apply the sand-coated filling sand-proof completion process which cannot be applied because the consolidation condition cannot be achieved in the ultra-deep ultra-shallow gas low-temperature reservoir to the ultra-deep ultra-shallow gas low-temperature reservoir, and simultaneously, the invention does not increase the complexity of the traditional circulating filling construction process, is simple and easy to implement, has strong operability, occupies short operation time of the ultra-deep ocean platform, and saves construction cost.

Inventors

DONG CHANGYIN
WANG HAOYU
XUE DONGYU
BAI LI
ZHOU TONG
LI NA
LI ZHANGYU

Assignees

中国石油大学(华东)

Dates

Publication Date: 20260505
Application Date: 20260306

Claims (7)

1. The method for optimizing construction of sand filling prevention well completion of ultra-deep water ultra-shallow gas low-temperature reservoir coating sand is characterized by comprising the following steps of: S1, a screen pipe coated sand circulation filling construction method for ensuring coated sand consolidation of an ultra-deep water ultra-shallow gas low-temperature reservoir comprises the following steps: The method comprises the steps of pumping thermal pretreatment liquid into a sieve sleeve annular space in a circulation channel, raising the original temperature of a reservoir in a near well region to a temperature range where coated sand can be solidified, pumping thermal sand-carrying liquid into the sieve sleeve annular space, and carrying out thermal sand-carrying liquid circulation filling; The ultra-deep water ultra-shallow gas low-temperature reservoir coated sand filling sand prevention completion optimization construction method further comprises the following steps: S2, designing the temperature and the liquid amount of a near-well reservoir in a heat treatment reservoir stage before circulating filling of the ultra-deep ultra-shallow gas low-temperature reservoir, wherein the design method of the temperature and the liquid amount of the near-well reservoir in the heat treatment reservoir stage before circulating filling of the ultra-deep ultra-shallow gas low-temperature reservoir carries out parameter design of heat pretreatment liquid based on low-temperature consolidation dynamics characteristics and a near-well stratum radial transient heat conduction rule, and carries out on-site construction parameter optimization based on the designed parameters, and the parameters of the heat pretreatment liquid comprise heat pretreatment liquid inlet temperature T p , heat pretreatment liquid pumping capacity q p and heat pretreatment liquid continuous injection time T p ; The parameter design of the thermal pretreatment liquid based on the low-temperature consolidation dynamics characteristic and the near-well stratum radial transient heat conduction rule comprises the following specific steps: Step A, determining an effective heating radius r e of a near-well reservoir or a continuous injection time t p of a thermal pretreatment liquid according to critical temperature propagation conditions; Step B, calculating heat quantity Q r required by the reservoir layer in the near well region to reach the lowest consolidation temperature of the coated sand based on the effective heating radius of the reservoir layer in the near well; Step C, calculating the inlet temperature T p of the heat pretreatment liquid and the pumping discharge capacity Q p of the heat pretreatment liquid based on the heat Q r required by the reservoir layer in the near-well region to reach the lowest consolidation temperature of the coated sand and the continuous injection time T p of the heat pretreatment liquid; The ultra-deep water ultra-shallow gas low-temperature reservoir coated sand filling sand prevention completion optimization construction method further comprises the following steps: S3, designing the design method of the sand gravel packing and displacement liquid amount of the ultra-deep water ultra-shallow gas low-temperature reservoir heat liquid coating: Step S31, establishing a quantitative analysis relation of the lowest inlet temperature of the hot-carrier fluid, the circulation filling duration time and the minimum circulation filling discharge capacity so as to realize the collaborative design of the lowest inlet temperature T s of the hot-carrier fluid, the circulation filling duration time T s and the minimum circulation filling discharge capacity q s , and ensuring that the temperature of a near-well area can be continuously not lower than the lowest consolidation temperature of coated sand and the consolidation can be completed within the circulation filling duration time T s in the hot-carrier fluid circulation filling process; And S32, calculating the volume of the displacement fluid so as to realize the full replacement of the annular space of the screen sleeve and the residual hot sand-carrying fluid in the screen pipe.
2. The method for optimizing the construction of the ultra-deep ultra-shallow gas low-temperature reservoir coated sand filling sand prevention well completion according to claim 1, wherein in the step S1, the original temperature of the reservoir in the near well area is raised to the lowest consolidation temperature of the coated sand.
3. The ultra-deep water ultra-shallow gas low-temperature reservoir coated sand filling sand prevention completion optimization construction method according to claim 2, wherein the step S1 specifically comprises: Step a, a thermal treatment reservoir stage, namely after a completion pipe string is put into a target well section and structural sealing is completed, pumping thermal pretreatment liquid into a screen pipe through a heat insulation oil pipe or a special circulating pipe string, entering a screen sleeve ring through a screen hole of the screen pipe, and raising the original temperature of the reservoir in a near-well area to the lowest consolidation temperature of coated sand; b, after the heat treatment reservoir stage is finished, pumping hot sand-carrying fluid containing coated sand into the sieve tube through a heat-insulating oil pipe or a special circulating pipe column, conveying the hot sand-carrying fluid to a sieve sleeve ring space with the coated sand, gradually depositing, accumulating and filling the sieve sleeve ring space and near-well defect space under the action of circulating flow to form a continuous and uniform particle accumulating layer; C, after the hot sand-carrying fluid circulation filling stage is completed, pumping a sand-free displacement fluid into the sieve tube through a heat-insulating oil tube or a special circulation tubular column, and fully displacing the residual hot sand-carrying fluid in the sieve tube and the empty interior of the sieve tube ring; And d, after the displacement stage is completed, closing the circulation channel and ending the construction.
4. The method for optimizing construction of the ultra-deep ultra-shallow gas low-temperature reservoir coated sand filling sand prevention well completion according to claim 1 is characterized in that the step A is characterized in that when the minimum liquid amount principle is met, namely the effective heating radius of a near-well reservoir is equal to the radius of a shaft and is a known amount, the continuous injection time t p of the thermal pretreatment liquid is calculated through the effective heating radius of the near-well reservoir, and when the continuous injection time t p of the thermal pretreatment liquid is a known amount, the effective heating radius of the near-well reservoir is calculated, and specifically as follows: The critical temperature propagation conditions are as follows: (1) Wherein, T c -the lowest consolidation temperature of coated sand, C, T 0 -the original temperature of a reservoir, C, T max -the highest allowable temperature of coated sand, C, erfc () -a complementary error function, calculated by a table lookup method in engineering, r e -the effective heating radius of a near-well reservoir, m, alpha-the thermal diffusion coefficient of a stratum, m 2 /s;t p -the continuous injection time of a thermal pretreatment liquid, s; According to the radial transient heat conduction theory, under the condition that the thermal pretreatment liquid is continuously injected and the continuous injection time t p of the thermal pretreatment liquid is known, the effective heating radius of the near-well reservoir is in an engineering simplified expression: (2) (3) (4) Wherein, xi-complementary error coefficient, dimensionless, lambda-stratum heat conductivity coefficient, W/(m.DEG C), rho f -stratum effective density, kg/m 3 ;c f -stratum equivalent specific heat capacity, J/(kg.DEG C); if the minimum liquid amount principle is satisfied, r e =r w calculates the continuous injection time t p of the thermal pretreatment liquid according to formula (4): (5) wherein r w is the radius of the shaft, m; and B, the heat required by the reservoir layer in the near well region to reach the minimum consolidation temperature of the coated sand is as follows: Simplifying the near zone into a homogeneous isotropic cylindrical stratum unit, ignoring the axial temperature gradient, and considering only radial heat conduction, the total heat required for raising the near zone from the reservoir original temperature T 0 to the lowest consolidation temperature T c of the coated sand is: (6) wherein, Q r is the heat required by the reservoir layer in the near well region to reach the minimum consolidation temperature of the coated sand, J is the effective length of the L-well section, m; -reservoir porosity,%; the step C comprises the following steps: Calculating the heating heat after heat loss correction: Considering heat transfer of shaft-stratum temperature difference and heat dissipation in the circulation process, and introducing a comprehensive thermal efficiency coefficient, the heating heat after heat loss correction is as follows: (7) Wherein, Q is the heating heat after heat loss correction, J, eta is the comprehensive heat efficiency coefficient, dimensionless, and recommended value is 0.6-0.8; Calculating the injection volume of the thermal pretreatment liquid: The effective heat provided by the pretreatment liquid in unit volume is as follows: (8) Wherein Q p -effective heat of unit volume of pretreatment liquid, J/m 3 ;ρ p -density of the pretreatment liquid, kg/m 3 ;c p -specific heat capacity of the pretreatment liquid, J/(kg DEG C), T p -inlet temperature of the pretreatment liquid, DEG C; The minimum injection volume required for the thermal pretreatment liquid is: (9) wherein V p is the minimum injection volume of the thermal pretreatment liquid, m 3 ;q p is the pumping displacement of the thermal pretreatment liquid, and m 3 /s; if the inlet temperature T p of the hot pretreatment liquid is known, calculating the pumping displacement q p of the hot pretreatment liquid according to the formula (10): (10) If the thermal pretreatment liquid pumping capacity q p is known, calculating the thermal pretreatment liquid inlet temperature T p according to formula (11): (11)。
5. The ultra-deep water ultra-shallow gas low-temperature reservoir coated sand filling sand prevention completion optimization construction method according to claim 1, wherein the on-site construction parameter optimization is performed based on designed parameters according to the following priority principles: principle a temperature priority principle: the thermal pretreatment liquid inlet temperature should be guaranteed as follows inequality to compensate for wellbore heat transfer losses: (12) principle b, minimum liquid amount principle, namely selecting the minimum injection volume required by the thermal pretreatment liquid under the condition of meeting the following principle: (13) Principle c, construction time constraint principle, namely controlling the continuous injection time T p of the thermal pretreatment liquid within an acceptable operation window of a deep water platform by improving the pumping discharge capacity q p of the thermal pretreatment liquid or the inlet temperature T p of the thermal pretreatment liquid.
6. The method for optimizing the construction of the ultra-deep water ultra-shallow gas low temperature reservoir coated sand filling sand prevention completion according to claim 1, wherein in the step S31, the lowest inlet temperature T s of the hot carrier fluid is calculated based on the transient radial heat conduction analytic solution, the circulating filling minimum displacement q s is obtained based on the lowest inlet temperature T s of the hot carrier fluid and the total heat constraint condition of the hot carrier fluid, so as to realize the collaborative design of the lowest inlet temperature T s of the hot carrier fluid, the circulating filling duration T s and the circulating filling minimum displacement q s , and the circulating filling liquid volume of the hot carrier fluid is calculated according to the circulating filling duration T s and the circulating filling minimum displacement q s .
7. The ultra-deep water ultra-shallow gas low-temperature reservoir coated sand filling sand prevention well completion optimization construction method according to claim 6, wherein, The step S31 specifically includes: Firstly, calculating the temperature of a hot sand-carrying fluid circulation filling inlet: in the circulating filling process of the hot sand-carrying fluid, the temperature of the well wall always meets the following constraint conditions: (14) Wherein, the Refers to the temperature at the borehole wall at time t; According to the transient radial heat conduction analytic solution, the temperature distribution of the reservoir layer at the radius r at the time t can be obtained: (15) In the formula, -At time T the radius is the temperature of the reservoir at r, r-radius extending towards the formation with the axis of the wellbore as centre, -T-hot carrier fluid circulation filling inlet temperature, °c, -T s -circulation filling duration, s; obtaining the lowest inlet temperature of hot-carrier sand fluid at the well wall r=r w : (16) Secondly, calculating the minimum displacement of cyclic filling: To ensure that the near zone remains no lower than the minimum consolidation temperature of the coated sand throughout the cyclic filling duration t s , the total heat provided by the hot carrier fluid must meet the energy requirements for formation temperature rise, subject to the constraints: (17) Based on equations (16) and (17), a cyclic fill minimum displacement is obtained: (18) Wherein q s -minimum discharge capacity of circulating filling, m 3 /s;r c -design consolidation control radius, m, rho s -density of hot sand-carrying fluid, kg/m 3 ;c s -specific heat capacity of hot sand-carrying fluid, J/(kg DEG C); Calculating the volume of the hot sand carrying circulating filling liquid: (19) Wherein, V s is the volume of the hot sand carrying circulation filling liquid, m 3 ; the volume of the displacing fluid in step S32 is calculated according to the following formula: (20) Wherein V d is the volume of the displacement liquid, m 3 , and beta is the construction safety margin coefficient, and the method is dimensionless.

Description

Sand-filling prevention well completion optimization construction method for ultra-deep water ultra-shallow gas low-temperature reservoir coating sand Technical Field The invention belongs to the technical field of oil and gas engineering, and particularly relates to an ultra-deep water ultra-shallow gas low-temperature reservoir coating sand filling sand prevention well completion optimization construction method. Background Deep (including deep land and deep water) oil gas resource development is a main field of oil gas energy development in China, wherein ultra-deep water ultra-shallow gas is an important resource type of deep oil gas. The geological reserves of ultra-deep water and ultra-shallow natural gas reach trillion parties at present. But the depth of the ultra-deep and ultra-shallow layer air layer is 1500-1700 m, the depth of burial under the seabed is about 150-300 m, and the ultra-deep and ultra-shallow layer air layer has the characteristics of shallow burial, low temperature (about 15 ℃), weak cementation and the like. The reservoir is weak diagenetic or even non diagenetic, and the problems of unstable and damaged reservoir structure and sand production easily occur in the exploitation process. Therefore, for ultra-deep water ultra-shallow gas reservoirs, the sand control completion technology is required to realize high-efficiency sand blocking and ensure the productivity of a gas well, and is required to have reliable well wall supporting capacity and long-term service stability, and has extremely high requirements on process applicability and engineering feasibility. Screen gravel packing is the dominant process technology for sand control completions in horizontal wells at sea, while coated sand has self-consolidating properties under downhole conditions. The screen pipe gravel packing and the coated sand are combined to form high-strength coated consolidation sand blocking and supporting barriers in the screen pipe and the well bore annulus, so that the core requirement of ultra-deep water ultra-shallow gas sand prevention completion can be effectively met, and the sand prevention well completion technology is a very promising sand prevention well completion technology. But this technology faces the following key problems: (1) The temperature of the ultra-deep water ultra-shallow gas reservoir in China is only about 15 ℃, the lowest consolidation temperature of the coated sand at home and abroad at present is 18-20 ℃, the higher the ambient temperature is, the easier the coated sand is consolidated, otherwise, the lower the temperature is, the harder the coated sand is consolidated, so that the existing coated sand cannot directly meet the sand prevention requirement of the ultra-deep water ultra-shallow gas low-temperature reservoir. (2) The lack of a specific technical scheme, an optimal design method and an implementation process technology with operability of sand prevention completion of ultra-deep and ultra-shallow gas low-temperature reservoir coating sand enables no clear feasible sand prevention completion process technology to exist in the existing ultra-deep and ultra-shallow gas. For example, chinese patent document CN110593810a proposes a method for heating and solidifying a circulating hot fluid of a pipe column to promote consolidation of an artificial well wall, and a new artificial well wall is molded at a damaged port of a screen pipe, so that the damaged screen pipe can be quickly repaired without determining the damaged position of the screen pipe, but the method is long in time consumption, high in consumed liquid, long in operation time of occupying a deepwater platform and high in cost. The method also does not give specific temperature and liquid amount design method, and is difficult to implement and apply. The Chinese patent document CN120719964A discloses a method for judging and evaluating an alternating injection and production instability mode of an air energy storage well coated sand layer, which comprises the steps of 1, determining initial state parameters of an evaluation object, determining flow in experimental evaluation according to a similarity criterion, 2, collecting parameters at two ends of the coated sand filling layer in the experimental process, classifying the alternating injection and production instability failure modes of the air energy storage well coated sand filling layer, identifying the instability failure modes, 3, calculating various indexes according to the collected parameters, and 4, carrying out production regulation and coated sand filling layer evaluation according to an index calculation result. However, the discrimination and evaluation method has definite application limitation, is only suitable for conventional air energy storage wells, mainly focuses on stability analysis and pattern recognition under the existing shaft conditions, belongs to the category of post discrimination and risk evaluation, does not consider th