SU829898A1 - Method of determining bottom pressure variations in wells - Google Patents

Description

The invention relates to hydrodynamic studies of formations and can be used in the oil industry. A known method for investigating deep-pumping wells with a register (and pressure with a deep manometer, lowered into squigine on a wire through the annular space tl3) to a decrease in the accuracy of pressure measurements as a result of failures of one or another mechanism of a pressure meter manometer caused by the latter strikes the column of the pump-and-compressor system or a well bore.In addition, a known research method can be applied only in those wells where the gap between the tubing string and the casing string allows the device to pass through. All of these factors ultimately affect the accuracy of hydrodynamic parameters There is also a method for determining changes in downhole pressure in water wells by measuring the pressure at the wellhead in the pump-compression pipes :: thermal insulation is created around the pump-compressor pipes aschuyu environment by starter hole to spout through the annulus 12. However, this method can only be applied in izlivayuschihs wells, i.e. in squiggins with high reservoir pressure. and construction, underground equipment, allowing the possibility of spout through the annulus. The purpose of the invention is to make it possible to determine the pressure change in non-draining wells equipped with hydrostatic pumping units, operating at pressures not lower than the liquid saturation pressure of the gas, by creating a hydraulic connection between the bottom hole and the wellhead. This goal is achieved due to the fact that the wellhead pressure is measured after the flow line of the pump is blocked, and the change in the back pressure is determined from the following relationship:

 T - l PVCT.

Others where DDRg and - change of bottomhole and wellhead pressure, kgf / cm, smaller and larger area of the pump plunger, cm L The drawing shows a schematic diagram of the device with which this method is carried out. After the differential plunger has reached the lower position, the surface power pump is shut off. At the same time, the plunger 1 starts to move upwards and the pumped-off medium rises through the tubing pipes 2 due to the energy accumulated in the supra-packer zone of the annular space 3 and the reservoir energy acting on the bottom plunger. In this way, a hydraulic connection of the well to the wellhead is achieved. At this time, with the energy discharging mode, by closing the valve on the discharge 4, and start recording the readings of the wellhead meter 5 in time until the pressure was restored. The resulting wellhead pressure recovery curve is converted into a bottomhole pressure recovery curve using the formula U and processed using known methods to determine the formation’s hydrodynamic parameters.

An example. Determination of reservoir parameters.

The flow rate to stop 5 106 m / day, the porosity of the reservoir m 0,18 effective power h 17,6 m; compressibility of oil / Jgc 11-10 cm / kgsg compressibility of the medium

with. 1-10 - large area of the differential plunger mm / smaller area of the plunger F; 32 mm;

area ratio | 1.75.

The results of the well study with the reduction of the pressure recovery curve at the wellhead are shown in the table.

By knowing the AP, f () dependence, we construct the bottomhole pressure recovery curve. Select a straight line segment and select two points by which we find the angular coefficient

1 l RP - l Pg 4t -,.,

 8.1-7.0

 1.41

4,158-3,380

829898

If i, the reservoir is found.

2.3 11.57 106

kh M 4N. 1.41 158.16 From here we can determine the coefficient of piezoconductivity (mpici fVj 158.16 1.760 (0.18-11 + 1) - 10-5 3012.5 Using the proposed method will allow to obtain an economic effect by making it possible to determine the hydrodynamic parameters of the layers in non-drainable wells equipped with hydraulic thrust pumping units, as well as by simplifying measurements of downhole parameters by creating a hydraulic connection between the bottom hole and the wellhead, which allows to eliminate such preparatory operations as well equipment incendiary devices (eccentric plates, breathers, etc.) and descent under-R

A method for determining the change in bottomhole pressure in wells equipped with tubing pipes by measuring the variation in wellhead pressure over time, characterized in that, in order to determine the pressure change in non-rising wells equipped with hydraulic pumping units, the wellhead pressure is measured after the discharge valve the pump line, and the bottom hole pressure change is determined from the following relationship:

- D RUST

Dr

G-1

where dR is the change in bottomhole pressure / 2.

laziness, kgf / cm;

Luster change in wellhead pressure, kgf / cm; F - smaller area of the plunger

pump cm

i large area of pump plunger, see

Sources of information taken into account in the examination

1. Repin H, H. and others. Technologists mechanized oil production. M., Nedra, 1976, p. 61-72.

15

2. USSR author's certificate 501148, cl. E 21 B 47/06, 01.30.76,

Claims (1)

Claim The method of determining changes in bottomhole pressure in wells equipped with tubing by measuring the change in wellhead pressure over time, characterized in that, in order to determine the change in pressure in non-flowing wells equipped with hydraulic rod pumping units, the wellhead pressure is measured after the flow line is closed pump, and the change in bottomhole pressure is determined from the following ratio: DR5 ⁱ * ^Δ Rust 'where dR _e - change in bottomhole pressure, kgf / cm ² ; Drew _c - change wellhead pressure, kgf / ^cm2; F, - smaller area of the pump plunger, cm F ^ - large area of the pump plunger, cm ² .