Abstract: This disclosure provides a method for channel state feedback in a non-simultaneous transmit and receive (NSTR) operation mode and the communication device thereof. The method implemented in a first communication device, the first communication device being configured with a plurality of links for communicating with a second communication device, the method including: receiving first data over a channel of a first link of the plurality of links; determining whether a channel of a second link of the plurality of links is idle in a case that no data is received over the channel of the second link and the first link and the second link belong to a non-simultaneous transmit and receive (NSTR) link pair; and transmitting a feedback frame over the channel of the first link, wherein the feedback frame includes a first field indicating whether the channel of the second link is idle.

Abstract: This disclosure provides a backoff counting method in a non-simultaneous transmit and receive (NSTR) operation mode and the communication device for the method. The method includes: configuring a plurality of backoff counters for counting backoff slots with no medium activity of channels of the plurality of links; synchronizing a count value of a first backoff counter of the plurality of backoff counters with a count value of a second backoff counter of the plurality of backoff counters, if the first backoff counter starts counting later than the second backoff counter or resumes counting after a pause, wherein the count value of the second backoff counter is smaller than that of the first backoff counter; and transmitting or receiving a signal on a channel of at least one of the plurality of links after all the backoff counters reach a predefined value.

Abstract: A gamma fusion computing method based on gamma probe parameters is provided, which relates to the technical field of oil drilling equipment while drilling, including: acquiring measurement values of two gamma probes in one continuous rotation period, and utilizing a mean value and a variance of the measurement values in the one rotation period as an evaluation reference value of each gamma probe; determining whether the gamma probes are abnormal, if the two gamma probes are both normal, utilizing the weight values to perform weight fusion on the measured values measured by two gamma probes, and if there is a gamma probe that is abnormal, then multiplying the average of the measured values of the normal gamma probe in the rotation period by 2 as a gamma output value for output. The gamma fusion computing method is capable of accurately determine the abnormal conditions of the gamma probes and effectively resolve the abnormal output.

Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses a drilling fluid additive composition comprising a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particle, and its modifying group includes a modifying copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant. The present invention further provides a pseudo oil-based drilling fluid suitable for horizontal shale gas wells containing the above composition.

Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses a drilling fluid additive composition comprising a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particle, and its modifying group includes a modifying copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant. The present invention further provides a pseudo oil-based drilling fluid suitable for horizontal shale gas wells containing the above composition.

Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses a high-density water-based drilling fluid suitable for horizontal shale gas wells comprising a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, a filler, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particle, and its modifying group includes a modifying copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; the filler consists of calcium carbonate of 1,600-2,500 mesh, calcium carbonate of 1,050-1,500 mesh, and calcium carbonate of 500-1,000 mesh at a weight ratio of 1:0.55-6:0.55-6; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant.

Abstract: The present invention discloses a bionic shale inhibitor, consisting of structural units denoted by formula (1) and structural units denoted by formula (2), wherein, the molar ratio of the structural units denoted by formula (1) to the structural units denoted by formula (2) is 0.2-6:1, and the weight-average molecular weight of the shale inhibitor is 800-4,000 g/mol. The present invention further provides a method for preparation of a bionic shale inhibitor. The present invention further provides a drilling fluid containing the bionic shale inhibitor. The bionic shale inhibitor disclosed in the present invention has high shale inhibition capability, and is environment-friendly and pollution-free.

Abstract: The present subject matter relates to an amphiphilic reservoir protecting agent, including structural units denoted by the following formula (1), (2), (3) and (4). The present subject matter further provides a method for preparation of an amphiphilic reservoir protecting agent. The present subject matter further provides a drilling fluid that contains the amphiphilic reservoir protecting agent. The amphiphilic reservoir protecting agent and drilling fluid obtained in the present subject matter have high reservoir protection property and high shale inhibition property.

Abstract: The present invention provides a biomimetic polymer for stabilizing wellbore, a method for preparation of the biomimetic polymer, and a drilling fluid. The polymer contains carboxymethyl chitosan that serves as a backbone and dopamine-derived groups grafted on the backbone. The polymer provided in the present invention can improve the strength of shale in the wellbore, seal the shale pores and reduce the filter loss of drilling fluid, and thereby attains an effect of stabilizing the wellbore in shale formation in drilling process.

Abstract: The present invention provides a biomimetic polymer for stabilizing wellbore, a method for preparation of the biomimetic polymer, and a drilling fluid. The polymer contains carboxymethyl chitosan that serves as a backbone and dopamine-derived groups grafted on the backbone. The polymer provided in the present invention can improve the strength of shale in the wellbore, seal the shale pores and reduce the filter loss of drilling fluid, and thereby attains an effect of stabilizing the wellbore in shale formation in drilling process.

Abstract: The present subject matter relates to an amphiphilic reservoir protecting agent, including structural units denoted by the following formula (1), (2), (3) and (4). The present subject matter further provides a method for preparation of an amphiphilic reservoir protecting agent. The present subject matter further provides a drilling fluid that contains the amphiphilic reservoir protecting agent. The amphiphilic reservoir protecting agent and drilling fluid obtained in the present subject matter have high reservoir protection property and high shale inhibition property.

Abstract: The present invention provides a biomimetic polymer for stabilizing wellbore, a method for preparation of the biomimetic polymer, and a drilling fluid. The polymer contains carboxymethyl chitosan that serves as a backbone and dopamine-derived groups grafted on the backbone. The polymer provided in the present invention can improve the strength of shale in the wellbore, seal the shale pores and reduce the filter loss of drilling fluid, and thereby attains an effect of stabilizing the wellbore in shale formation in drilling process.

Abstract: The present invention provides a biomimetic polymer for stabilizing wellbore, a method for preparation of the biomimetic polymer, and a drilling fluid. The polymer contains carboxymethyl chitosan that serves as a backbone and dopamine-derived groups grafted on the backbone. The polymer provided in the present invention can improve the strength of shale in the wellbore, seal the shale pores and reduce the filter loss of drilling fluid, and thereby attains an effect of stabilizing the wellbore in shale formation in drilling process.