Application of mud non-falling treatment system

With the rapid development of economy, environmental protection has been paid more and more attention, which has a great impact on the exploration industry.

As the 'blood' of drilling industry, mud plays the role of protecting well wall, carrying cuttings, cold reagents, etc. in the drilling process. In addition, a large amount of chemical reagents are needed in the process of preparing mud. Therefore, there are new environmental protection requirements for the treatment of waste mud.

As the drilling mud non-ground treatment system is gradually being applied and has achieved good results, it has been recognized by relevant departments and gradually promoted.

Working principle of drilling mud non-ground treatment system

The drilling mud non-ground treatment system is to decompose the waste mud into water, cuttings, and mud cake through a set of treatment processes. The water is directly purified to meet the standards of reuse or direct discharge. The cuttings can be directly discharged or retained after dehydration and drying. The mud cake (or mixed with dried cuttings) is mixed with cement, curing agent and water in proportion and stirred evenly to make concrete, bricks, etc., so as to realize the recycling of solid waste residue. The whole treatment system includes: cuttings separation unit; mud sand water separation unit; filter press drying unit; wastewater purification unit.

Cuttings separation

The cuttings separation unit includes a first tank body, a vibrating screen arranged in the first tank body, and a drying screen arranged outside the first tank body. The first tank body is connected to the mud-sand separation unit, and the drying screen is connected to the mixing tank body. A first guide channel is provided between the vibrating screen and the drying screen, and a first baffle plate is provided in the first guide channel.

As the drilling work starts and goes deeper, the original mixed mud circulates through the wellbore, carrying a large amount of cuttings. The mud flows out of the wellbore and directly passes through the vibrating screen, thereby separating the larger cuttings in the mud. The separated cuttings are directly discharged or reserved for use after drying. In this stage, no chemical reagents are added, and mechanical equipment is used directly to separate the cuttings and mud. After separation, part of the mud is continuously reused for production, which will reduce the discharge of waste slurry and save some costs.

Mud, sand and water separation

The mud, sand and water separation unit includes a second tank body and a third tank body connected in sequence, a desander and a desilter in the two tank bodies, a centrifuge in the third tank body, and a screw feeder outside the second tank body and the third tank body. The feeding length of the screw feeder covers the arrangement length of the desander, desilter and centrifuge, and the screw feeder is connected to the mud and water storage and regulating box; a second guide channel is provided between the discharge port of the desander, desilter and centrifuge and the screw feeder, and a second baffle plate is provided in the second guide channel;

The second guide channel is inclined from the corresponding discharge port to the screw feeder. After the rock cuttings separation, the waste mud is separated into primary mud mortar, rock cuttings and waste liquid. The primary mud mortar is passed into the mud and sand separation unit, the rock cuttings are collected, and the waste liquid is passed into the mixing tank. Then, the primary mud mortar is separated into secondary mud mortar and primary mud mortar through the mud and sand separation unit. The secondary mud mortar is recycled, and the primary mud mortar is passed into the mud and water storage and regulating box. After the mud and water storage and regulating box, it is passed into the mixing tank with speed and quantity adjustment, and then the reagent is added through the dosing barrel. After being stirred by the agitator, the secondary mud and sand liquid is obtained, and the secondary mud and sand liquid is passed into the filter press drying unit.

Filter pressing and drying

The filter pressing and drying unit includes a dryer arranged near the clean water tank, a conveyor connected to the dryer, and a liquid supply pump arranged between the dryer and the mixing tank. The secondary mud and sand liquid passes through the filter pressing and drying unit to obtain mud cake and wastewater. After the mud cake is collected, cement, curing agent and water are added in proportion and mixed and stirred evenly to make concrete, bricks, etc., and the wastewater is passed into the purification treatment unit.

Wastewater purification

The wastewater purification unit includes a purification treatment body connected to the filter pressing and drying unit, and a clean water tank body connected to the purification treatment body. The clean water tank body is connected to the mixing tank body and the dosing barrel body. The wastewater is treated by the purification treatment body to obtain purified water and stored in the clean water tank body. The clean water tank body can supply water to the mixing tank body and the dosing barrel body.

The cuttings separation unit, mud and sand water separation unit, filter pressing and drying unit and wastewater purification unit are all skid-mounted in the drilling construction area. The drilling mud non-ground processing system also includes a spare tank and a storage tank arranged adjacent to the cuttings separation unit and the mud-sand separation unit. The spare tank and the storage tank are used to replace damaged tanks and store processed secondary mud respectively.

The drilling mud non-ground treatment system also includes a collection unit for receiving rock cuttings and mud cakes, and a solidification treatment unit connected to the collection unit.

The application of drilling mud non-ground technology has great advantages over traditional treatment methods.

First, the waste residue in the waste mud is recycled and treated by the mud non-ground treatment system, and the waste water is recycled and reused, which greatly reduces the well site area, shortens the early drilling preparation time, and saves construction time and cost;

Second, the waste mud is harmlessly treated, and the treated mud is recycled, saving construction costs;

Third, environmental pollution is treated from the source, and the waste mud is basically treated with drilling, shortening the previous treatment cycle, and the waste water is continued to be recycled after treatment, such as: preparing mud, configuring treatment agents, etc., saving some costs;

Fourth, it adapts to the current development situation in my country and meets the requirements of green exploration.

As the country and local governments have shown great importance to environmental protection, many regions have clearly pointed out that waste mud cannot be treated by direct discharge, burial, in-situ solidification burial, etc. This requires our exploration companies to change their previous treatment methods. Especially when conducting geothermal exploration in some famous scenic spots, environmental problems are particularly prominent. Local governments have strict environmental supervision and impose severe penalties on companies that cause pollution. Therefore, it provides a good development prospect for the non-ground treatment system for drilling mud.