RU2536515C1 - Method of productivity recovery and commissioning of non-operating oil and gas wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method includes the conducting of repair and insulating works, "moderate" perforation of the production casing by a power drill with the working member equipped with hydromonitor channels, injection of sealing composition into the punched holes, bridge installation inside the production casing and subsequent re-perforation and development of the productive formation. Meanwhile during a single tripping of the perforator "moderate" perforation of the production casing is made in the interval below the productive formation and above the water producing formation. A simultaneous sealing of the formed holes of the interval and the bridge installation inside the production casing by means of supply of cementing composition through the perforator are performed. The perforator is backwashed when it is lifted to the productive formation, which is re-perforated and developed by the same perforator.

EFFECT: saving of time and resources for the method implementation at the expense of execution of several actions in one tripping.

Description

The invention relates to the oil and gas industry, namely, the restoration of idle oil and gas wells with low filtration and capacitive properties (FES) and closely spaced water-oil (VNK) or gas-water (GVK) contacts.

The well-known method of advanced drilling in the development of oil and gas fields, in which wells are drilled, without waiting for the arrangement of the field and the supply of pipelines to the wells, diverting the production of the well to the producing field. The well is drilled, the production string is perforated, inflow from the reservoir is called up, after which the well is jammed with clay or brine of the appropriate density and preserved for the period of waiting for commissioning (up to several years, as, for example, at the Yamburgskoye field in Western Siberia). Prolonged presence of the well in anticipation of being connected to the pipeline and the producing field under the influence of clay or salt solutions negatively affects the reservoir properties of the reservoir rocks and the productive characteristics of the well. It is impossible to develop a well using standard methods, for example, by reducing back pressure on the formation. In such cases, it is usually practiced to re-open the reservoir by drilling second trunks, fracturing, or reperforating the initial perforation interval.

There is a method of restoring productivity and putting into operation idle oil and gas wells, including the production of repair and insulation works, opening the reservoir in the casing and putting the well into operation [see Kustyshev A.V. et al. Restoring the productivity of idle oil and gas wells / Oil and gas: problems of subsoil use, production and transportation: Materials of scientific and technical. Conf., dedicated to the 90th birthday of V.I. Muravlenko. Tyumen, Tsogu, 2002, p.112].

The disadvantage of this method is that when restoring the productivity of idle wells with complex reservoirs and low reservoir properties by perforating a production string with high-power cumulative perforators, there is a violation of the tightness of the cement ring behind the string — its complete or partial destruction, which leads to the occurrence of annular flows of water and gas .

A known method of restoring productivity and putting into operation idle oil and gas wells, including the production of repair and insulation works, opening a reservoir in the casing and putting the well into operation [RF Application 98116654, 04.09.98, publ. 06/20/2000. Bull. No. 17].

The disadvantage of this method is that when restoring the productivity of idle wells with complex reservoirs and low reservoir properties by drilling a second wellbore while re-opening the reservoir beyond the contamination of the near-wellbore zone of the formation (FZP), high costs are required for drilling a new wellbore with a low probability of falling into productive zone, especially in reservoirs with lenses and interlayers of rocks having fairly good FES.

The closest solution adopted as a prototype is a method of restoring productivity and putting into operation idle oil and gas wells according to the patent of the Russian Federation No. 2231630, announced November 15, 2002, publ. 06/27/2004.

The disadvantage of the prototype is that repair and insulation work while restricting water inflows with repeated perforation (reperforation) of the reservoir is carried out in several stages with the descent and lifting of the necessary equipment for each of the following stages. Stage 1: produce a “gentle” perforation of the production string, for example, by shooting perforators or sandblasting perforation (GSP) in the interval of the flooded part of the reservoir below the BHC or GWC by 1-2 meters, then the tubing assembly with the perforator is raised up. Stage 2: lower the tubing to the perforated interval and pump through the newly formed perforation holes a water-insulating composition forming a water-proof screen, pushing the water deeper into the reservoir, then raise the tubing. Stage 3: the perforator is lowered again and the production string is “sparing” perforated below the initial perforation interval and 1-2 meters above the BHA or GWC, after which the perforator is again removed to the surface. Stage 4: the tubing is lowered again and the sealing composition, for example, a composition based on polyvinyl alcohol, is pumped into the annular space through the newly formed openings above the BHC or GWC. Then, cement is pumped through the tubing to prevent behind-the-casing flow of water and gas, installing a cement bridge inside the production casing blocking the newly formed perforations. Then they pick up the tubing. Stage 5: having installed a perforator on the tubing, the assembly is again lowered into the well and re-opening the reservoir by sparing the perforation of the production string in the initial perforation interval with the perforation depth extending radially outside the contaminated zone, they call the inflow, development and input wells in operation.

The task underlying the invention is to eliminate these drawbacks and ensure reliable restoration of well productivity, prevent the influx of formation water to the bottom and the occurrence of annular flows of water and gas along the cement ring while reducing capital costs.

The technical result consists in accelerating the process carried out in one tripping operation, which saves time and material costs.

The technical result is achieved by the fact that in the method of restoring productivity and putting into operation idle oil and gas wells, including repair and insulation work, “sparing” perforation of the production string below the reservoir, injection of the sealing composition into perforations, installation of a bridge inside the production string and subsequent reperforation and development of the reservoir, according to the invention, “gentle” perforation of the production string produce hydromech nical perforator working body equipped hydromonitor channels, in the range below the producing formation and above the aquifer to the injection of the sealant composition through the channels and setting the perforator bridge from the same composition within the production tubing and the subsequent reperforatsiyu and development of the productive formation produced in the same perforator.

These processes are carried out in one round-trip operation of any type of hydromechanical perforator having a working body with hydraulic monitoring channels.

The inventive method is as follows.

A hydromechanical perforator installed on a tubing string, which is equipped with a working body with hydromonitor channels forming a gap or hole in the production string, for example a slotted or piercing perforator, is lowered into the well and “gentle” perforation of the production string is produced in the interval below the watered part of the reservoir and above the aquifer layer. A sealing composition is pumped into the formed perforation slots or holes through the hydromonitor channels of the perforator, for example, the composition of the quick setting cement slurry (BSTS), thereby creating a blocking screen, and a bridge is placed inside the production casing of the same material to block the formed perforation holes (slots) to prevent behind-the-casing flows of water and gas. Then the perforator is lifted to the reservoir and the perforator is backwashed from the remnants of the sealing composition. At the end of the flushing, the working fluid (acidic, hydrocarbon solvent, surfactant, etc.) is pumped through the tubing under pressure, and the production string is reperforated with a hydraulic reservoir treatment. After perforation of the productive formation, it is mastered by known methods, producing an inflow through the hydraulic monitor channels of the perforator.

Thus, the inventive method is carried out in one tripping operation, which saves time, material and energy costs.

Claims (1)

A method of restoring productivity and putting into operation idle oil and gas wells, including repair and insulation work, “gentle” perforation of the production casing with a hydromechanical perforator with a working body equipped with hydraulic monitoring channels, injection of the sealing composition into the perforations, installation of a bridge inside the production casing and subsequent reperforation and development of the reservoir, characterized in that for one round-trip operation of the perforator wear a “gentle” perforation of the production string in the interval below the reservoir and above the aquifer, carry out simultaneous sealing of the formed openings of the interval and install the bridge inside the production string by feeding the grouting composition through the perforator, backwash the perforator when it rises to the reservoir, reperforation and development which carry out the same punch.