Our Oil & Gas
Methods of searching of oil and gas in Russia correspond to the highest standards. On The first stage are carried out seismic surveys for the identification of perspective oil and gas bearing structures. Then we can start the phase of drilling exploration. With sufficient funding, the whole cycle of search and evaluation activities at the major new oil field is carried out for 5-10 years or more. "New technologies in exploration drilling develop in three main areas - improving efficiency, reducing costs and minimizing the impact on the environment - says Herman Kaledin, ch. Geologist of OAO Achimgaz (N. Urengoy). - So, during the exploration on small and medium-sized (up to 5 km) depths are gradually being introduced methods with a reduced diameter hole, which makes it possible to reduce the terms of drilling and completion operations, reduce the size of the drill head (bits), power of installation, use pipes of smaller diameter. This allows you to significantly reduce the cost of work on the insufficiently studied deposits, during the second and appraisal drilling and peripheral areas. At the same time due to increasing of depth and complexity of the geological structure of the newly discovered fields we require more powerful rigs, so increases the costs for construction of wells.
As a result, almost the only cost-justified opportunity to make a preliminary map of the deposit can be seismic exploration. "Even in a crisis, when the amount of drilling exploration has been halved, the amount of seismic work fell only by 10% - said Valery Nesterov, an analyst at Troika Dialog (Moscow). - It is less expensive job than drilling, so companies try to hold them more thoroughly to further reduce the risks of drilling. However, after receiving the seismic data you would still need to drill holes or parametric estimates, as only they can be used to establish the nature of saturation of the reservoir and to evaluate their productivity, which is necessary for the industrial exploitation of the deposit.
About drilling
Bore receives the rotation from the rotor installed on the ground surface above the wellhead, through the column of drilling pipes. Breeds of any hardness can be destroyed over the whole area of working face or on the ring with the formation in the center of undisturbed column (core) the hole, which is required for the study of crackable drill core. Depending on how the core was raised we differ core drilling with core receiver and core hydrotransport.
In the first case Cairn rises in the inner barrel on thin steel rope inside the drill string, the second inner tube is transported by the flow of washing fluid. Coring with exploration drilling carried out to study the geological section.
Drilling depth rotational (including rotor) way can reach the 10 km, diameter of the hole varies from 76 to 590 mm.
Drilling without coring is possible in hard rock categories I-XII (for drillability) at sufficiently high speeds of well’s deepening. In soft rocks, drilling speed can reach 100 mph, and at solid rocks at great depths it is reduced up to 1 m / h.
Choosing URB
Currently, several Russian companies commercially produce the installations of exploratory drilling. It should be understood that despite the statements of manufacturers URB are used in the first place not only in o hydrocarbon exploration in the traditional sense, but in exploration and for other purposes where it is necessary to drill wells and lift out of them pipes of small diameter and limited weight. Consequently, mostly rational URB can be used for blast hole drilling, testing and refurbishing, re- and appraisal drilling.
URB are most commonly used in rotary drilling, in accordance with its specialization. Machines from different manufacturers vary in many respects. First of all in drilling depth: 50 m to 100 m to 300 m to 1000 m. during The evaluation of deposits and re-drilling for oil / gas are typically used installations with depth of 1000 meters or more. URB are mobile installations and move independently due to wheeled or tracked chassis. Typically, drilling machine rigidly tied to a particular chassis and does not allow removal.
URB consists of the following main units: frame (chassis); drive (engine); rotor (rotator); elevator (or feeder drill rods); compressor for blowing or flushing pump (depending on the technology of removal of rocks on the surface). The total plant capacity can be up to 4 MW, weight - 1000 tons
Russia's largest manufacturer of mobile drilling rigs and components destined for the test drilling for oil, gas, water, etc. is OAO Kungursky Machine Works (SC “Kungur”), It produces machines Type-URB-ZAZ (4 versions) on the MAZ-5337, Ural-4320-1912-40 or a trailer OZTP-8470. Basic mechanisms of modifications 05, 051 and 13 have pneumatic control, which enhances efficiency and reduces the force on the lever. Conventional drilling depth (depending on the diameter of pipes) is 300-700 m.
Public society «Machine-Building Plant. V.V. Vorovs'kogo” produces five models: URB-2A2, URB -2D3, and URB-2A2D on different chassis, and also URB-4T (on the frame of the tractor skidding ТТ-4М or ТТ-4) ; URB-1B2 on the chassis of the crawler transporter GAZ-34037. Drilling depth of cored wells with washing is 300-350 m, the process of filing is 5200 mm.
The first in the nomenclature of “Plant Stroydormash” is fully Hydroficated machine URB-2M, which has nominal drilling depth of up to 100 m. The basis for its creation served constructive developments on the basis of a joint project with the German firm «Lutz Kurth». Feature of URB-2M is its modular type that allows assembly on a different chassis with different kinds of packaging arrangement. The plant also offers URB-531 on the basis MTLBu and novelty - URB-51 for drilling exploratory wells and boreholes with selection or without coring rotary-percussive rotary or impact-driven piles way. Maximum diameter of auger drill - no less than 300 mm, the longitudinal course of Rotator - 5200 mm.
The drilling rig URB-2, 5A public “Kemerovo Drilling Equipment Plant” is designed to drill deep into the water (artesian) wells, geophysical and structural wells to a depth of 200 m by rotating drill pipes with a diameter 60.3 mm and a depth of 300 meters by pipes that are 50 mm in diameter with a clearance hole flushing, as well as for drilling of group wells by screws.
The main supplier of machine tools for drilling is public society UZTM (Uralmash). Also on the Russian machines are assembled and other domestic and foreign drilling benches.
Trends
There is a growing use of mobile units such as the BA in geological survey, especially deep drilling (water rotary with a straight face flushing), UBS, plant of rotation (UVB, UBV, AVB) and screw (UH) drilling, mobile drilling units (PBU), Mobile plants such as MBU (for rotary and downhole drilling motors). About the latest EnergyLand.info wrote in the publication "Drilling: on the agenda - mobility".
Today's oil and gas companies do not run too costly works on the rating and re-drilling of small and medium depths, what allows them more fully master already prospected deposits. They tend to install and operate the exploration by rotary drilling. However, due to the complex nature of new oil and gas fields, the application of the URB and similar installations gradually and finally shifts to the exploration of other non-hydrocarbon resources.
Material is prepared by: Oleg Nikitin, EnergyLand.info
On the first photo: mobile drilling rig PBU-1200 (photo by “Altaygeomash”
Translation by: Mukhametyanov Timur