348 results about "Lost circulation" patented technology

A method and composition is provided for sealing a subterranean zone penetrated by a well bore to restore lost circulation. In one embodiment, the composition comprises a pellet comprising a mixture of lost circulation materials (LCMs).

A settable thixotropic material comprises a thixotrope and a settable substance, the material being capable of gelling reversibly in a gelling time of less than 60 seconds. The thixotrope conveniently comprises a fine grained clay, especially smectite clays, e.g. hectorites. It is preferred to use synthetic smectite type clay colloids, and goods results have been obtained with the synthetic clay known as Laponite RDS. The settable material conveniently comprises cement, particularly Portland cement. The thixotropic material finds use generally in oilwell applications, e.g. to plug lost circulation zones, to repair damaged or corroded casing, as grouts, and to limit annular gas migration. The material also finds particular application in techniques for completion of horizontal wells completed with slotted or pre-drilled liners.

The present invention provides cement compositions comprising a strength-enhancing lost circulation material, and methods for cementing using such cement compositions. Exemplary embodiments of the cement compositions comprise cement, water, and a strength-enhancing lost circulation material. Optionally, other additives suitable for inclusion in cement compositions may be added.

A viscous aqueous high density well treatment fluid composition stable at high temperature containing a surfactant and inorganic salts is described. Methods of preparing the fluid and increasing the stability and viscosity of the fluid are given. The fluid is useful for wellbore cleanout, hydraulic fracturing, gravel packing, completion, acid diversion, lost circulation reduction, well killing, cementing, selective water shutoff, and fracture fluid diversion.

The invention relates to a plugging agent during well drilling in oil and gas field, and particularly to a high efficient plugging agent for severe lost circulation. The components are, by weight: 18-25% of walnut shell powder, 8-10% of sawdust, 8-10% of cottonseeds, 10-15% of hull powder, 20-30% of active plugging agents, and 15-25% of elastic rubber granules, and the raw materials are mixed uniformly to obtain a high efficient plugging agent for well drilling. According to the invention, the fibrous plugging agent with granules is formed by mixing natural plant inert materials, a synergistic agent, and a reinforcing agent with a certain preparation ratio. The plugging agent of the invention has the advantages of wide covering area for leak stopping, high pressure bearing capacity, good plugging effect, high success rate for disposable leak stopping, simple on-site preparation process, and reliable and safe construction, which can achieve the purposes of reducing loss of lost circulation and saving comprehensive cost. The high efficient plugging agent of the invention is applicable to leak stopping operations under various lost circulation conditions with good leak stopping effect and high success rate, and is superior to other types of plugging agents.

A method of preventing or treating lost circulation during the drilling of a well comprises the addition, at concentration ranging between about 0.5 and 6 pounds per barrel, of water-dispersible fibers having a length between about 10 and 25 mm, for instance glass or polymer fibers, to a pumped aqueous base-fluid including solid particles having an equivalent diameter of less than 300 μm The base-fluid with the solid particles can be the drilling fluid or a small-volume pill specially pumped for curing lost circulation.

A lost circulation material and method for well treatment employing the material that is effective at sealing or plugging small fissures and large fractures and has utility over a wide range of temperatures, including high temperatures. The material has an optimized bimodal particle distribution and optionally has a polymer flocculent or water swellable polymer.

The present invention relates to subterranean cementing operations and, more particularly, to cement composition that include improved lost circulation materials, and methods of using such cement compositions in subterranean formations. In certain exemplary embodiments, the improved lost circulation materials include inelastic particles of polyethylene, polystyrene and/or polypropylene. Optionally, the cement compositions also may include additives such as fly ash, a surfactant, a dispersant, a fluid loss control additive, a conventional lost circulation material, an generator, a retarder, a salt, a mica, fiber, a formation-conditioning agent, fumed silica, bentonite, expanding additives, microspheres, weighting materials, or a defoamer.

An improved composition and method is provided for preventing or alleviating lost circulation during the drilling of wellbores in subterranean formations, and particularly during the drilling of oil and gas wells. The method is suited for horizontal and directional wells as well as more vertical wells. The composition of the invention comprises a synergistic blend of resilient, angular, carbon-based material and a water-swellable, crystalline synthetic polymer. The method employs the composition of the invention in preventing lost circulation.

In accordance with aspects of the present disclosure, techniques for predicting, classifying, preventing, and remedying drilling fluid circulation loss events are disclosed. Tools for gathering relevant data are disclosed, and techniques for interpreting the resultant data as giving rise to an actual or potential drilling fluid lost circulation event are also disclosed.

A rapidly dehydrating lost circulation material (LCM) composition is provided. The LCM composition may include a carrier fluid, volcanic ash, a viscosifier, and date tree rachis fibers. The carrier fluid may be water and the viscosifier may be a cellulosic microfiber. The LCM composition may form a rapidly dehydrating loss control slurry (RDLCS). The LCM composition may be formed by mixing the carrier fluid, the volcanic ash, the viscosifier, and the date tree rachis fibers in a mixer to form a homogenous mixture. Methods of lost circulation control and manufacture of a rapidly dehydrating LCM are also provided.