41results about How to "Lower burst pressure" patented technology

The invention belongs to the field of petroleum engineering and relates to a shale gas reservoir pre-fracture composite acid solution and its preparation method and application. The composite acid solution comprises the following components: Component a) at least one component of hydrochloric acid, hydrofluoric acid, fluorboric acid, phosphoric acid, formic acid and acetic acid; and Component b) a corrosion inhibitor, a discharge aiding agent, a ferric iron stabilizer and a clay stabilizer. The composite acid solution containing different acids is selected for different reservoirs. Rock core corrosion ratio is 25-30%. A certain rock core corrosion ratio is maintained, and borehole wall collapse caused by too high corrosion ratio is also prevented. The corrosion inhibitor, the discharge aiding agent, the ferric iron stabilizer and the clay stabilizer which are used as additives have good compatibility with acid. The composite acid solution provided by the invention has advantages of fast dissolving speed, uniform mixing, high corrosion inhibition efficiency, high surface activity, good clay stabilizing effect and wide range. Applicable temperature of the composite acid solution is 20-180 DEG C. by the use of the composite acid solution, normal construction of large-scale fracturing of long horizontal-section shale gas wells can be guaranteed under the condition of existing equipment capacity.

The invention belongs to the technical field of weakening treatment of hard and difficult roofs of coal seams, in particular to a method for weakening hard roofs of coal seams. Solve the problem that in the actual mining process, the hard roof is overhanging in a large area and it is difficult to collapse naturally. After the collapse, it mostly collapses in a large area and has a large impact range. 1) Drilling settings, 2) Ground drilling, 3) Chemical erosion, 4) hydraulic fracturing, 5) surface drainage. The invention can not only give full play to the softening effect of the chemical solution on the hard roof rock, but also give full play to the effect of hydraulic fracturing on the cutting and cracking of the rock, thereby softening the hard roof rock.

The invention relates to a drilling technology in the field of petroleum exploration and development, in particular to a method for determining drilling fluid density in salt-gypsum layer deflection. The method for determining drilling fluid density in salt-gypsum layer deflection comprises the following steps of: (1) establishing a salt-gypsum layer creep model under the variable-curvature and variable-azimuth conditions; (2) according to the salt-gypsum layer creep model, establishing a salt-gypsum layer borehole wall deformation model under the conditions of drilling fluid density, borehole curvature and borehole azimuth; (3) establishing a relationship chart of the drilling fluid density, borehole curvature and borehole azimuth; and (4) according to the relationship chart established in the step (3), determining the reasonable drilling fluid density. By using the method provided by the invention, the appropriate drilling fluid density, deflection azimuth and deflection curvature can be preferably selected, thereby reducing the drilling fluid density to satisfy the minimum burst pressure of the stratum, effectively preventing borehole undergauge and avoiding complex downhole circumstances.

An oil-gas-well hydraulic-fracturing down-hole low-frequency hydraulic-pulse generating device comprises a composite frustum cylinder body assembly, an upper connector and a lower connector, wherein the upper connector is arranged at the upper end of the composite frustum cylinder body assembly, and the lower connector is arranged at the lower end of the composite frustum cylinder body assembly. A composite frustum plunger matched with the composite frustum cylinder body assembly is arranged in the composite frustum cylinder body assembly, a through-hole is formed in the composite frustum plunger, and semi-circular grooves used for preventing sand blocking are evenly distributed on the periphery of the composite frustum plunger; and a reset spring is arranged on the lower portion of the composite frustum plunger, and a bearing seat is arranged at the lower end of the reset spring. After the up-down differential pressure of the composite frustum plunger reaches a certain value, operating liquid descends to compress the reset spring, when the composite frustum plunger descends, the flow area on the periphery of the composite frustum plunger gradually increases, the up-down differential pressure of the composite frustum plunger decreases, and the reset spring pushes the composite frustum plunger to ascend; and thus, reciprocating type vibration is generated, and low-frequency hydraulic pulse is generated in output fracturing fluid. According to the oil-gas-well hydraulic-fracturing down-hole low-frequency hydraulic-pulse generating device, based on the working displacement range of the hydraulic-fracturing operation, low-frequency hydraulic-pulse output of a hydraulic driving mode is achieved, and the hydraulic-fracturing effect can be improved on the whole.

The invention discloses a selective re-fracturing technology for an old well of an oil field. The selective re-fracturing technology for the old well of the oil field is designed to achieve re-transformation of the old well of the oil field effectively. According to the selective re-fracturing technology for the old well of the oil field, perforation of an interval needing to be transformed is achieved by assembling a pipe column, placing the pipe column in the well and dragging the pipe column, fracturing of a lowest new interval is achieved by packing an upper packer and an intermediate packer, unpacking is conducted, and the pipe column is dragged to a second new transformed interval. According to the selective re-fracturing technology for the old well of the oil field, a duct with the large diameter and the deep penetration is formed through hydraulic jet perforation, and thus fracturing pressure can be effectively reduced; the requirements for supporting facilities of a well mouth and the steel grade of a sleeve are lowered by means of the advantage of the dual-packing and single-clamping fracturing technology. The selective re-fracturing technology for the old well of the oil field has the advantages that the pipe column is simple in structure, the construction method is flexible, operation is convenient, the efficiency is high, re-transformation of the old well of the oil field can be achieved effectively, re-fracturing of the transformed interval can be achieved, and perforating and fracturing of the new interval can also be achieved integrally.

The invention discloses a vertical well orientated hydraulic jet multi-stage fracturing method for an oil and gas well. The method includes the following steps of well flushing, well killing and drifting scrapping. A guiding head, a rotatable casing collar locator, a repeatable-setting packer, an oriented hydraulic jet gun, a safety joint, an oriented pup joint and an oil tube oriented hydraulic jet multi-stage fracturing string are sequentially connected to the tail end of an oil tube; after the string enters the well, the position of the jetting tool is localized accurately through the rotatable casing collar locator; the string is rotated at the mouth of the well to determine the orientation corresponding to a spray nozzle of the oriented hydraulic jet gun; after orientation is determined, setting of the repeatable-setting packer is performed, perforating fluid enters from an oil tube pump to perform sand blasting perforation, and oil jacket annular space sand fracturing is performed; after fracturing construction is ended, the oil tube is lifted to unpack the repeatable-setting packer. With the method, the operation period is short, the demand that during fracturing, crack initiation is performed in the minimum main stress direction can be met, construction pressure is decreased, and the recovery efficiency of the oil and gas well is substantially improved.

Present invention refers to a method for overcoming salt rock layer creepage utilizing drilling fluid density and chlorides concentration relationship concentration relationship. It contains 1, to make hole boring with sampling and test sample processing, 2, taking four experiment test samples, to proceed creep test to each test sample, taking multiple level temperature and multiple level loading compound experiment mode to obtain creep test straining and timetable, 3, establishing salt rock creepage constitutive relation equation i.e. creep stress-rate of strain relation equation through curve matching method, 4, establishing well bore necked-in rate and drilling fluid density relation equation,5, taking the rest of four test samples, to proceed salting in experiment, corresponded salting in dissolution rate and chlorides pH indicator relation curve, establishing salting in rate and chlorides pH indicator relational model through nonlinear regression, 6, establishing drilling fluid density, temperature and chlorides pH indicator graph of relation edition, determining rational drilling fluid density and chlorides concentration to overcame salt bed creepage according to steps 6 graph of relation edition to salt bed well drilling in same zone block with experiment well core.

The invention discloses a low-frequency hydraulic pulse generating device and method for reservoir temporary-plugging diversion fracturing. The low-frequency hydraulic pulse generating device comprises a cylinder body, an upper connector and a lower connector, wherein the upper connector and the lower connector are connected to the upper end and the lower end of the cylinder body correspondingly; a piston matched with the cylinder body is arranged in the cylinder body; the upper portion of the cylinder body is of a cylinder structure, and the lower portion of the cylinder body is of a cone structure; a throttling device is arranged at the upper end of the piston; a flow guiding through hole is formed inside the piston; a throttling through hole is formed in the center of the throttling device and vertically communicate with the flow guiding through hole, and the diameter of the throttling through hole can become larger under erosion of fracturing liquid; a reset spring is arranged at the bottom of the piston; and a first pressure relief hole , a second pressure relief hole and a third pressure relief hole are further circumferentially formed in the side wall, corresponding to the piston, of the cylinder body. According to the low-frequency hydraulic pulse generating device and method, based on the working displacement ranges of the injection stages of a temporary-plugging diversion repeated hydraulic fracturing operation plugging agent, a prepad fluid, a sand-carrying fluid and a displacing fluid, low-frequency hydraulic pulse output in a hydraulic driving mode is achieved, and the temporary-plugging diversion repeated hydraulic fracturing effect can be improved overall.

The invention discloses equipment and method for controlling an industrial and mining limestone roof of a well through acid fracturing, and relates to the technical field of mining. The method comprises the following steps of constructing a group of parallel drill holes between working face frames close to a coal wall side and a goaf side; sealing the drill holes, starting a high-pressure pump to inject acid liquor into the drill holes, stopping injecting when the pressure of the pipeline reaches 10 MPa, and maintaining the pressure for 5-10 min; after pressure maintaining is finished, starting the high-pressure pump again to conduct limestone roof acid fracturing for 30 min; after fracturing is finished, turning off the high-pressure pump, and carrying out pressure maintaining for 5-10 min; after pressure maintaining is finished, relieving the pipeline pressure, and taking a hole packer; and repeating the steps until fracturing of all the drilled holes is completed. According to the method, the acid fracturing mode is adopted for treating the industrial and mining hard limestone roof of the well, through dissolution of acid liquor to limestone, on one hand, the construction pressure in the fracturing process can be reduced, on the other hand, the opening degree of a fracturing crack can be increased, the meshing effect of rock blocks on the two sides of the fractured crack is reduced, and sufficient caving of the limestone roof is facilitated.

The invention discloses a low-cost and high-efficiency transformation process method for a low-permeability reservoir of an offshore oilfield, and belongs to the technical field of oilfield reservoir transformation. The method mainly comprises the following steps: step 1, preferably selecting a measure horizon and a layered transformation part; 2, the maximum limited pressure of the shaft is calculated; 3, cable deflagration fracturing operation is carried out; 4, rock layering expansion operation is carried out; step 5, layered acidification operation; and 6, starting the pump to flow back the residual acid and recovering production. According to the method, the modification effect of the low-permeability reservoir of the offshore oilfield can be effectively improved through selective combination of several low-cost modification processes, and the problem of conventional hydraulic fracturing caused by limitation of platform space and water sources of the offshore oilfield, large span of the low-permeability reservoir, high operation cost and long period is solved; and a new thought is provided for low-cost and high-efficiency transformation of the low-permeability reservoir of the offshore oilfield.

The invention discloses a horizontal well pumping perforating surface-fixed orientation-point clustering perforator detonation transfer conversion device. The device comprises a detonation transfer conversion joint, a fixing cap for fixing a detonation transfer tube, a first conductive sheet and a second conductive sheet for electric conduction, a spring for pressing the second conductive sheet, insulating sleeves, insulating pads, a gun body, a bearing, a positioning ring, perforating bullet clusters, the detonation transfer tube, a detonating cord, a control key, locking pieces, a bearing cap, a bearing sleeve, an upper through wire and a lower through wire. According to the device, in order to achieve detonation transfer between gun strings and transmission of electric signals under anyangle rotation state of gun carriers, wires for transmitting the electric signals and detonating cords installed on the gun carriers in the perforating gun strings rotate along with the gun carriers,an intermediate detonation transfer conversion device is installed between the two gun strings, moving wires respectively fixed on the gun carriers in the two gun strings can be rotated freely in guns along with the gun carriers, the electrical signals can be reliably transmitted, the detonation transfer tube is used for docking, and the detonation transfer can be effectively implemented.

The invention provides a fracturing preposed authigenic acid system and a fracture reduction method thereof. The fracturing preposed authigenic acid system comprises authigenic acid mother liquor A, authigenic acid mother liquor B and authigenic acid mother liquor C, wherein the authigenic acid mother liquor A is a paraformaldehyde aqueous solution, and the polymerization degree n is 10-100; the authigenic acid mother liquor B is an ammonium chloride aqueous solution; and the authigenic acid mother liquor C is an ammonium fluoride aqueous solution. According to the fracturing preposed authigenic acid system, the authigenic acid mother liquor A, the authigenic acid mother liquor B and the authigenic acid mother liquor C can be mixed at the bottom of a well on the basis of efficient transportation and no corrosion of a tubular column, and acid liquor is spontaneously and continuously generated, so that the purpose of no corrosion of the tubular column is achieved. Meanwhile, the generated acid liquor reacts with rock minerals, so that drilling and completion fluid pollution in a near shaft zone can be efficiently relieved, the porosity and permeability of a reservoir stratum are increased, the fluid absorption capacity of the reservoir stratum is improved, the fracture pressure of the reservoir stratum is reduced, the displacement of construction can be increased, and the effect of large-scale yield increase and transformation is achieved.

The invention provides a stratum transformation method, which comprises the following steps of: 1, performing refined segmentation on a reservoir according to reservoir conditions; 2, perforation operation is carried out to form perforations in all the divided sections; 3, fracturing operation is conducted through a fracturing pipe column, in the step 3, pre-acid is pumped into the fracturing pipe column to be used for corrosion of pollution of slurry and cement slurry to a fracture system in the drilling and completion process before main fractures are formed for the divided sections, according to the stratum transformation method, the reservoir is segmented firstly, the transformation layer position can be defined, and the stratum transformation efficiency can be improved; and in the subsequent fracturing operation process, the pre-acid is pumped to corrode the pollution of slurry and cement slurry to a crack system in the drilling and completion process, meanwhile, the fracturing pressure is reduced, the construction difficulty is reduced, the reservoir transformation effect is improved, and the yield is increased.

The invention discloses an acidizing ball seat suitable for an ultra-deep carbonate rock gas reservoir and a using method thereof.The acidizing ball seat comprises a ball seat body, an acidizing channel and a ball receiving shaft core, the ball seat body is arranged at the bottom of a packer, a main channel communicated with a center pipe of the packer is arranged in the ball seat body, a reducing part is arranged in the main channel, and the ball receiving shaft core is in a funnel shape; the fitting reducing part is arranged in the main channel and can coaxially move up and down along the main channel in the ball seat body, and the acidification channel is arranged on the inner wall of the ball seat body, communicates the main channel with a shaft annulus and is movably shielded by the ball seat body; when in use, the ball seat is mounted at the bottom of a K344 packer, the ball seat and the K344 packer are tripped into a fractured well together, the packer is allowed to carry out slurry reverse replacement when acid fracturing is not carried out, and a setting ball is put into the ball seat for pressurization when fracturing operation is carried out, so that an acidification channel is opened, acid fracturing is carried out smoothly, and smooth acidification construction is guaranteed.